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' Generates Concentric Magic Squares of order 9

' Tested with Office 2007 under Windows 7

```Sub MgcSqr9d()

Dim a(81), b(81), c(81)

y = MsgBox("Locked", vbCritical, "Routine MgcSqr9d")
End

n2 = 0: n9 = 0
m1 = 1: m2 = 81: s1 = 369

'   Generate data

Sheets("Klad1").Select

t1 = Timer

a(41) = 41: b(41) = 41: c(41) = 41

For j81 = 16 To 16                                          'a(81)
If b(j81) = 0 Then b(j81) = j81: c(81) = j81 Else GoTo 810
a(81) = j81

a(1) = 82 - a(81)
If a(1) <= 0 Or a(1) > 81 Then GoTo 10
If b(a(1)) = 0 Then b(a(1)) = a(1): c(1) = a(1) Else GoTo 10

For j80 = 81 To 81                                          'a(80)
If b(j80) = 0 Then b(j80) = j80: c(80) = j80 Else GoTo 800
a(80) = j80

a(8) = 82 - a(80)
If a(8) <= 0 Or a(8) > 81 Then GoTo 80
If b(a(8)) = 0 Then b(a(8)) = a(8): c(8) = a(8) Else GoTo 80

For j79 = 79 To 79                                          'a(79)
If b(j79) = 0 Then b(j79) = j79: c(79) = j79 Else GoTo 790
a(79) = j79

a(7) = 82 - a(79)
If a(7) <= 0 Or a(7) > 81 Then GoTo 70
If b(a(7)) = 0 Then b(a(7)) = a(7): c(7) = a(7) Else GoTo 70

For j78 = 76 To 76                                          'a(78)
If b(j78) = 0 Then b(j78) = j78: c(78) = j78 Else GoTo 780
a(78) = j78

a(6) = 82 - a(78)
If a(6) <= 0 Or a(6) > 81 Then GoTo 60
If b(a(6)) = 0 Then b(a(6)) = a(6): c(6) = a(6) Else GoTo 60

For j77 = 74 To 74                                          'a(77)
If b(j77) = 0 Then b(j77) = j77: c(77) = j77 Else GoTo 770
a(77) = j77

a(5) = 82 - a(77)
If a(5) <= 0 Or a(5) > 81 Then GoTo 50
If b(a(5)) = 0 Then b(a(5)) = a(5): c(5) = a(5) Else GoTo 50

For j76 = 7 To 7                                          'a(76)
If b(j76) = 0 Then b(j76) = j76: c(76) = j76 Else GoTo 760
a(76) = j76

a(4) = 82 - a(76)
If a(4) <= 0 Or a(4) > 81 Then GoTo 40
If b(a(4)) = 0 Then b(a(4)) = a(4): c(4) = a(4) Else GoTo 40

For j75 = 9 To 9                                          'a(75)
If b(j75) = 0 Then b(j75) = j75: c(75) = j75 Else GoTo 750
a(75) = j75

a(3) = 82 - a(75)
If a(3) <= 0 Or a(3) > 81 Then GoTo 30
If b(a(3)) = 0 Then b(a(3)) = a(3): c(3) = a(3) Else GoTo 30

For j74 = 15 To 15                                          'a(74)
If b(j74) = 0 Then b(j74) = j74: c(74) = j74 Else GoTo 740
a(74) = j74

a(73) = 369 - a(74) - a(75) - a(76) - a(77) - a(78) - a(79) - a(80) - a(81)
If a(73) <= 0 Or a(73) > 81 Then GoTo 730
If b(a(73)) = 0 Then b(a(73)) = a(73): c(73) = a(73) Else GoTo 730
a(9) = 82 - a(73)
If a(9) <= 0 Or a(9) > 81 Then GoTo 90
If b(a(9)) = 0 Then b(a(9)) = a(9): c(9) = a(9) Else GoTo 90
a(2) = 82 - a(74)
If a(2) <= 0 Or a(2) > 81 Then GoTo 20
If b(a(2)) = 0 Then b(a(2)) = a(2): c(2) = a(2) Else GoTo 20

For j72 = 80 To 80                                          'a(72)
If b(j72) = 0 Then b(j72) = j72: c(72) = j72 Else GoTo 720
a(72) = j72

a(64) = 82 - a(72)
If a(64) <= 0 Or a(64) > 81 Then GoTo 640
If b(a(64)) = 0 Then b(a(64)) = a(64): c(64) = a(64) Else GoTo 640

For j71 = 65 To 65                                          'a(71)
If b(j71) = 0 Then b(j71) = j71: c(71) = j71 Else GoTo 710
a(71) = j71

a(11) = 82 - a(71)
If a(11) <= 0 Or a(11) > 81 Then GoTo 110
If b(a(11)) = 0 Then b(a(11)) = a(11): c(11) = a(11) Else GoTo 110

For j70 = 64 To 64                                          'a(70)
If b(j70) = 0 Then b(j70) = j70: c(70) = j70 Else GoTo 700
a(70) = j70

a(16) = 82 - a(70)
If a(16) <= 0 Or a(16) > 81 Then GoTo 160
If b(a(16)) = 0 Then b(a(16)) = a(16): c(16) = a(16) Else GoTo 160

For j69 = 26 To 26                                          'a(69)
If b(j69) = 0 Then b(j69) = j69: c(69) = j69 Else GoTo 690
a(69) = j69

a(15) = 82 - a(69)
If a(15) <= 0 Or a(15) > 81 Then GoTo 150
If b(a(15)) = 0 Then b(a(15)) = a(15): c(15) = a(15) Else GoTo 150

For j68 = 24 To 24                                          'a(68)
If b(j68) = 0 Then b(j68) = j68: c(68) = j68 Else GoTo 680
a(68) = j68

a(14) = 82 - a(68)
If a(14) <= 0 Or a(14) > 81 Then GoTo 140
If b(a(14)) = 0 Then b(a(14)) = a(14): c(14) = a(14) Else GoTo 140

For j67 = 22 To 22                                          'a(67)
If b(j67) = 0 Then b(j67) = j67: c(67) = j67 Else GoTo 670
a(67) = j67

a(13) = 82 - a(67)
If a(13) <= 0 Or a(13) > 81 Then GoTo 130
If b(a(13)) = 0 Then b(a(13)) = a(13): c(13) = a(13) Else GoTo 130

For j66 = 63 To 63                                          'a(66)
If b(j66) = 0 Then b(j66) = j66: c(66) = j66 Else GoTo 660
a(66) = j66

a(65) = 287 - a(66) - a(67) - a(68) - a(69) - a(70) - a(71)
If a(65) <= 0 Or a(65) > 81 Then GoTo 650
If b(a(65)) = 0 Then b(a(65)) = a(65): c(65) = a(65) Else GoTo 650
a(12) = 82 - a(66)
If a(12) <= 0 Or a(12) > 81 Then GoTo 120
If b(a(12)) = 0 Then b(a(12)) = a(12): c(12) = a(12) Else GoTo 120

For j63 = 78 To 78                                          'a(63)
If b(j63) = 0 Then b(j63) = j63: c(63) = j63 Else GoTo 630
a(63) = j63

a(55) = 82 - a(63)
If a(55) <= 0 Or a(55) > 81 Then GoTo 550
If b(a(55)) = 0 Then b(a(55)) = a(55): c(55) = a(55) Else GoTo 550

For j62 = 21 To 21                                          'a(62)
If b(j62) = 0 Then b(j62) = j62: c(62) = j62 Else GoTo 620
a(62) = j62

a(56) = 82 - a(62)
If a(56) <= 0 Or a(56) > 81 Then GoTo 560
If b(a(56)) = 0 Then b(a(56)) = a(56): c(56) = a(56) Else GoTo 560

For j61 = 29 To 29                                          'a(61)
If b(j61) = 0 Then b(j61) = j61: c(61) = j61 Else GoTo 610
a(61) = j61

a(21) = 82 - a(61)
If a(21) <= 0 Or a(21) > 81 Then GoTo 210
If b(a(21)) = 0 Then b(a(21)) = a(21): c(21) = a(21) Else GoTo 210

For j60 = 30 To 30                                          'a(60)
If b(j60) = 0 Then b(j60) = j60: c(60) = j60 Else GoTo 600
a(60) = j60

a(24) = 82 - a(60)
If a(24) <= 0 Or a(24) > 81 Then GoTo 240
If b(a(24)) = 0 Then b(a(24)) = a(24): c(24) = a(24) Else GoTo 240

For j59 = 46 To 46                                          'a(59)
If b(j59) = 0 Then b(j59) = j59: c(59) = j59 Else GoTo 590
a(59) = j59

a(23) = 82 - a(59)
If a(23) <= 0 Or a(23) > 81 Then GoTo 230
If b(a(23)) = 0 Then b(a(23)) = a(23): c(23) = a(23) Else GoTo 230

For j58 = 49 To 49                                          'a(58)
If b(j58) = 0 Then b(j58) = j58: c(58) = j58 Else GoTo 580
a(58) = j58

a(57) = 205 - a(58) - a(59) - a(60) - a(61)
If a(57) <= 0 Or a(57) > 81 Then GoTo 570
If b(a(57)) = 0 Then b(a(57)) = a(57): c(57) = a(57) Else GoTo 570
a(25) = 82 - a(57)
If a(25) <= 0 Or a(25) > 81 Then GoTo 250
If b(a(25)) = 0 Then b(a(25)) = a(25): c(25) = a(25) Else GoTo 250
a(22) = 82 - a(58)
If a(22) <= 0 Or a(22) > 81 Then GoTo 220
If b(a(22)) = 0 Then b(a(22)) = a(22): c(22) = a(22) Else GoTo 220

For j54 = 77 To 77                                          'a(54)
If b(j54) = 0 Then b(j54) = j54: c(54) = j54 Else GoTo 540
a(54) = j54

a(46) = 82 - a(54)
If a(46) <= 0 Or a(46) > 81 Then GoTo 460
If b(a(46)) = 0 Then b(a(46)) = a(46): c(46) = a(46) Else GoTo 460

For j53 = 27 To 27                                          'a(53)
If b(j53) = 0 Then b(j53) = j53: c(53) = j53 Else GoTo 530
a(53) = j53

a(47) = 82 - a(53)
If a(47) <= 0 Or a(47) > 81 Then GoTo 470
If b(a(47)) = 0 Then b(a(47)) = a(47): c(47) = a(47) Else GoTo 470

For j52 = 47 To 47                                          'a(52)
If b(j52) = 0 Then b(j52) = j52: c(52) = j52 Else GoTo 520
a(52) = j52

a(48) = 82 - a(52)
If a(48) <= 0 Or a(48) > 81 Then GoTo 480
If b(a(48)) = 0 Then b(a(48)) = a(48): c(48) = a(48) Else GoTo 480

For j51 = 38 To 38                                          'a(51)
If b(j51) = 0 Then b(j51) = j51: c(51) = j51 Else GoTo 510
a(51) = j51

a(31) = 82 - a(51)
If a(31) <= 0 Or a(31) > 81 Then GoTo 310
If b(a(31)) = 0 Then b(a(31)) = a(31): c(31) = a(31) Else GoTo 310

For j50 = 43 To 43                                          'a(50)
If b(j50) = 0 Then b(j50) = j50: c(50) = j50 Else GoTo 500
a(50) = j50

a(49) = 123 - a(50) - a(51)
If a(49) <= 0 Or a(49) > 81 Then GoTo 490
If b(a(49)) = 0 Then b(a(49)) = a(49): c(49) = a(49) Else GoTo 490
a(42) = 164 - a(50) - 2 * a(51)
If a(42) <= 0 Or a(42) > 81 Then GoTo 420
If b(a(42)) = 0 Then b(a(42)) = a(42): c(42) = a(42) Else GoTo 420
a(40) = -82 + a(50) + 2 * a(51)
If a(40) <= 0 Or a(40) > 81 Then GoTo 400
If b(a(40)) = 0 Then b(a(40)) = a(40): c(40) = a(40) Else GoTo 400
a(33) = -41 + a(50) + a(51)
If a(33) <= 0 Or a(33) > 81 Then GoTo 330
If b(a(33)) = 0 Then b(a(33)) = a(33): c(33) = a(33) Else GoTo 330
a(32) = 82 - a(50)
If a(32) <= 0 Or a(32) > 81 Then GoTo 320
If b(a(32)) = 0 Then b(a(32)) = a(32): c(32) = a(32) Else GoTo 320

For j45 = 14 To 14                                          'a(45)
If b(j45) = 0 Then b(j45) = j45: c(45) = j45 Else GoTo 450
a(45) = j45

a(37) = 82 - a(45)
If a(37) <= 0 Or a(37) > 81 Then GoTo 370
If b(a(37)) = 0 Then b(a(37)) = a(37): c(37) = a(37) Else GoTo 370

For j44 = 28 To 28                                          'a(44)
If b(j44) = 0 Then b(j44) = j44: c(44) = j44 Else GoTo 440
a(44) = j44

a(38) = 82 - a(44)
If a(38) <= 0 Or a(38) > 81 Then GoTo 380
If b(a(38)) = 0 Then b(a(38)) = a(38): c(38) = a(38) Else GoTo 380

For j43 = 48 To 48                                          'a(43)
If b(j43) = 0 Then b(j43) = j43: c(43) = j43 Else GoTo 430
a(43) = j43

a(39) = 82 - a(43)
If a(39) <= 0 Or a(39) > 81 Then GoTo 390
If b(a(39)) = 0 Then b(a(39)) = a(39): c(39) = a(39) Else GoTo 390
a(34) = 123 - a(43) - a(52) + a(57) - a(61)
If a(34) <= 0 Or a(34) > 81 Then GoTo 340
If b(a(34)) = 0 Then b(a(34)) = a(34): c(34) = a(34) Else GoTo 340
a(30) = -41 + a(43) + a(52) - a(57) + a(61)
If a(30) <= 0 Or a(30) > 81 Then GoTo 300
If b(a(30)) = 0 Then b(a(30)) = a(30): c(30) = a(30) Else GoTo 300

For j36 = 13 To 13                                          'a(36)
If b(j36) = 0 Then b(j36) = j36: c(36) = j36 Else GoTo 360
a(36) = j36

a(28) = 82 - a(36)
If a(28) <= 0 Or a(28) > 81 Then GoTo 280
If b(a(28)) = 0 Then b(a(28)) = a(28): c(28) = a(28) Else GoTo 280

For j35 = 25 To 25                                          'a(35)
If b(j35) = 0 Then b(j35) = j35: c(35) = j35 Else GoTo 350
a(35) = j35

a(29) = 82 - a(35)
If a(29) <= 0 Or a(29) > 81 Then GoTo 290
If b(a(29)) = 0 Then b(a(29)) = a(29): c(29) = a(29) Else GoTo 290
a(26) = -123 + a(29) + a(38) + a(47) + a(56) + a(65) - a(71)
If a(26) <= 0 Or a(26) > 81 Then GoTo 260
If b(a(26)) = 0 Then b(a(26)) = a(26): c(26) = a(26) Else GoTo 260
a(20) = 205 - a(29) - a(38) - a(47) - a(56) - a(65) + a(71)
If a(20) <= 0 Or a(20) > 81 Then GoTo 200
If b(a(20)) = 0 Then b(a(20)) = a(20): c(20) = a(20) Else GoTo 200
a(17) = 287 - a(26) - a(35) - a(44) - a(53) - a(62) - a(71)
If a(17) <= 0 Or a(17) > 81 Then GoTo 170
If b(a(17)) = 0 Then b(a(17)) = a(17): c(17) = a(17) Else GoTo 170

For j27 = 10 To 10                                          'a(27)
If b(j27) = 0 Then b(j27) = j27: c(27) = j27 Else GoTo 270
a(27) = j27

a(19) = 82 - a(27)
If a(19) <= 0 Or a(19) > 81 Then GoTo 190
If b(a(19)) = 0 Then b(a(19)) = a(19): c(19) = a(19) Else GoTo 190
a(18) = 287 - a(27) - a(36) - a(45) - a(54) - a(63) - a(72) + a(73) - a(81)
If a(18) <= 0 Or a(18) > 81 Then GoTo 180
If b(a(18)) = 0 Then b(a(18)) = a(18): c(18) = a(18) Else GoTo 180
a(10) = 82 - a(18)
If a(10) <= 0 Or a(10) > 81 Then GoTo 100
If b(a(10)) = 0 Then b(a(10)) = a(10): c(10) = a(10) Else GoTo 100

n9 = n9 + 1
GoSub 2650 'Print results (squares)
'                                   GoSub 2645 'Print results (selected numbers)

b(c(10)) = 0: c(10) = 0
100 b(c(18)) = 0: c(18) = 0
180 b(c(19)) = 0: c(19) = 0
190 b(c(27)) = 0: c(27) = 0
270 Next j27

b(c(17)) = 0: c(17) = 0
170 b(c(20)) = 0: c(20) = 0
200 b(c(26)) = 0: c(26) = 0
260 b(c(29)) = 0: c(29) = 0
290 b(c(35)) = 0: c(35) = 0
350 Next j35
b(c(28)) = 0: c(28) = 0
280 b(c(36)) = 0: c(36) = 0
360 Next j36

b(c(30)) = 0: c(30) = 0
300 b(c(34)) = 0: c(34) = 0
340 b(c(39)) = 0: c(39) = 0
390 b(c(43)) = 0: c(43) = 0
430 Next j43
b(c(38)) = 0: c(38) = 0
380 b(c(44)) = 0: c(44) = 0
440 Next j44
b(c(37)) = 0: c(37) = 0
370 b(c(45)) = 0: c(45) = 0
450 Next j45

b(c(32)) = 0: c(32) = 0
320 b(c(33)) = 0: c(33) = 0
330 b(c(40)) = 0: c(40) = 0
400 b(c(42)) = 0: c(42) = 0
420 b(c(49)) = 0: c(49) = 0
490 b(c(50)) = 0: c(50) = 0
500 Next j50
b(c(31)) = 0: c(31) = 0
310 b(c(51)) = 0: c(51) = 0
510 Next j51
b(c(48)) = 0: c(48) = 0
480 b(c(52)) = 0: c(52) = 0
520 Next j52
b(c(47)) = 0: c(47) = 0
470 b(c(53)) = 0: c(53) = 0
530 Next j53
b(c(46)) = 0: c(46) = 0
460 b(c(54)) = 0: c(54) = 0
540 Next j54

b(c(22)) = 0: c(22) = 0
220 b(c(25)) = 0: c(25) = 0
250 b(c(57)) = 0: c(57) = 0
570 b(c(58)) = 0: c(58) = 0
580 Next j58
b(c(23)) = 0: c(23) = 0
230 b(c(59)) = 0: c(59) = 0
590 Next j59
b(c(24)) = 0: c(24) = 0
240 b(c(60)) = 0: c(60) = 0
600 Next j60
b(c(21)) = 0: c(21) = 0
210 b(c(61)) = 0: c(61) = 0
610 Next j61
b(c(56)) = 0: c(56) = 0
560 b(c(62)) = 0: c(62) = 0
620 Next j62
b(c(55)) = 0: c(55) = 0
550 b(c(63)) = 0: c(63) = 0
630 Next j63

b(c(12)) = 0: c(12) = 0
120 b(c(65)) = 0: c(65) = 0
650 b(c(66)) = 0: c(66) = 0
660 Next j66
b(c(13)) = 0: c(13) = 0
130 b(c(67)) = 0: c(67) = 0
670 Next j67
b(c(14)) = 0: c(14) = 0
140 b(c(68)) = 0: c(68) = 0
680 Next j68
b(c(15)) = 0: c(15) = 0
150 b(c(69)) = 0: c(69) = 0
690 Next j69
b(c(16)) = 0: c(16) = 0
160 b(c(70)) = 0: c(70) = 0
700 Next j70
b(c(11)) = 0: c(11) = 0
110 b(c(71)) = 0: c(71) = 0
710 Next j71
b(c(64)) = 0: c(64) = 0
640 b(c(72)) = 0: c(72) = 0
720 Next j72

b(c(2)) = 0: c(2) = 0
20  b(c(9)) = 0: c(9) = 0
90  b(c(73)) = 0: c(73) = 0
730 b(c(74)) = 0: c(74) = 0
740 Next j74
b(c(3)) = 0: c(3) = 0
30  b(c(75)) = 0: c(75) = 0
750 Next j75
b(c(4)) = 0: c(4) = 0
40  b(c(76)) = 0: c(76) = 0
760 Next j76
b(c(5)) = 0: c(5) = 0
50  b(c(77)) = 0: c(77) = 0
770 Next j77
b(c(6)) = 0: c(6) = 0
60  b(c(78)) = 0: c(78) = 0
780 Next j78
b(c(7)) = 0: c(7) = 0
70  b(c(79)) = 0: c(79) = 0
790 Next j79
b(c(8)) = 0: c(8) = 0
80  b(c(80)) = 0: c(80) = 0
800 Next j80
b(c(1)) = 0: c(1) = 0
10  b(c(81)) = 0: c(81) = 0
810 Next j81

t2 = Timer

t10 = Str(t2 - t1) + " sec., " + Str(n9) + " Solutions for sum" + Str(s1)
y = MsgBox(t10, 0, "Routine MgcSqr9d")

End

'   Print results (selected numbers)

2645 For i1 = 1 To 81
Cells(n9, i1).Value = a(i1)
Next i1

Return

'   Print results (squares)

2650 n2 = n2 + 1
If n2 = 5 Then
n2 = 1: k1 = k1 + 10: k2 = 0
Else
If n9 > 1 Then k2 = k2 + 10
End If
Cells(k1 + 1, k2 + 1).Select

i3 = 0
For i1 = 1 To 9
For i2 = 1 To 9
i3 = i3 + 1
Cells(k1 + i1, k2 + i2).Value = a(i3)
Next i2
Next i1

Return

End Sub
```

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