' Generates Concentric Lozenge Squares of order 7

' Tested with Office 2007 under Windows 7

```Sub MgcSqr7b()

Dim a1(50), a(25), b1(50), b(50), c(25), a7(50), c7(50)

y = MsgBox("Locked", vbCritical, "Routine MgcSqr7b")
End

n2 = 0: n3 = 0: n9 = 0: n10 = 0: k1 = 1: k2 = 1

t1 = Timer

For i1 = 1 To 49
a1(i1) = i1: b1(i1) = i1
Next i1
m1 = 1: m2 = 49: s1 = 125

For j100 = 2 To 27
Cells(k1, 1).Value = j100

a(7) = Sheets("Center3").Cells(j100, 1):  b(a(7)) = a(7)
a(8) = Sheets("Center3").Cells(j100, 2):  b(a(8)) = a(8)
a(9) = Sheets("Center3").Cells(j100, 3):  b(a(9)) = a(9)
a(12) = Sheets("Center3").Cells(j100, 4): b(a(12)) = a(12)
a(13) = Sheets("Center3").Cells(j100, 5): b(a(13)) = a(13)
a(14) = Sheets("Center3").Cells(j100, 6): b(a(14)) = a(14)
a(17) = Sheets("Center3").Cells(j100, 7): b(a(17)) = a(17)
a(18) = Sheets("Center3").Cells(j100, 8): b(a(18)) = a(18)
a(19) = Sheets("Center3").Cells(j100, 9): b(a(19)) = a(19)

'   Generate Squares

For j25 = m1 + 1 To m2 - 1 Step 2                                      'a(25) even
If b(a1(j25)) = 0 Then b(a1(j25)) = a1(j25): c(25) = a1(j25) Else GoTo 250
a(25) = a1(j25)

a(1) = 0.4 * s1 - a(25)
If a(1) < a1(m1) Or a(1) > a1(m2) Then GoTo 10
If b1(a(1)) = 0 Then GoTo 10
If b(a(1)) = 0 Then b(a(1)) = a(1): c(1) = a(1) Else GoTo 10

For j24 = m1 To m2 Step 2                                              'a(24) odd
If b(a1(j24)) = 0 Then b(a1(j24)) = a1(j24): c(24) = a1(j24) Else GoTo 240
a(24) = a1(j24)

a(4) = 0.4 * s1 - a(24)
If a(4) < a1(m1) Or a(4) > a1(m2) Then GoTo 40
If b1(a(4)) = 0 Then GoTo 40
If b(a(4)) = 0 Then b(a(4)) = a(4): c(4) = a(4) Else GoTo 40

For j23 = m1 To m2 Step 2                                              'a(23) odd
If b(a1(j23)) = 0 Then b(a1(j23)) = a1(j23): c(23) = a1(j23) Else GoTo 230
a(23) = a1(j23)

a(3) = 0.4 * s1 - a(23)
If a(3) < a1(m1) Or a(3) > a1(m2) Then GoTo 30
If b1(a(3)) = 0 Then GoTo 30
If b(a(3)) = 0 Then b(a(3)) = a(3): c(3) = a(3) Else GoTo 30

For j22 = m1 To m2 Step 2                                              'a(22) odd
If b(a1(j22)) = 0 Then b(a1(j22)) = a1(j22): c(22) = a1(j22) Else GoTo 220
a(22) = a1(j22)

a(21) = s1 - a(22) - a(23) - a(24) - a(25)
If CInt(a(21) / 2) <> a(21) / 2 Then GoTo 210                          'a(21) even
If a(21) < a1(m1) Or a(21) > a1(m2) Then GoTo 210
If b1(a(21)) = 0 Then GoTo 210
If b(a(21)) = 0 Then b(a(21)) = a(21): c(21) = a(21) Else GoTo 210

a(5) = 0.4 * s1 - a(21)
If a(5) < a1(m1) Or a(5) > a1(m2) Then GoTo 50
If b1(a(5)) = 0 Then GoTo 50
If b(a(5)) = 0 Then b(a(5)) = a(5): c(5) = a(5) Else GoTo 50

a(2) = 0.4 * s1 - a(22)
If a(2) < a1(m1) Or a(2) > a1(m2) Then GoTo 20
If b1(a(2)) = 0 Then GoTo 20
If b(a(2)) = 0 Then b(a(2)) = a(2): c(2) = a(2) Else GoTo 20

For j20 = m1 To m2 Step 2                                              'a(20) odd
If b(a1(j20)) = 0 Then b(a1(j20)) = a1(j20): c(20) = a1(j20) Else GoTo 200
a(20) = a1(j20)

a(16) = 0.4 * s1 - a(20)
If a(16) < a1(m1) Or a(16) > a1(m2) Then GoTo 160
If b1(a(16)) = 0 Then GoTo 160
If b(a(16)) = 0 Then b(a(16)) = a(16): c(16) = a(16) Else GoTo 160

For j15 = m1 To m2 Step 2                                              'a(15) odd
If b(a1(j15)) = 0 Then b(a1(j15)) = a1(j15): c(15) = a1(j15) Else GoTo 150
a(15) = a1(j15)

a(11) = 0.4 * s1 - a(15)
If a(11) < a1(m1) Or a(11) > a1(m2) Then GoTo 110:
If b1(a(11)) = 0 Then GoTo 110
If b(a(11)) = 0 Then b(a(11)) = a(11): c(11) = a(11) Else GoTo 110

a(10) = 0.6 * s1 - a(15) - a(20) + a(21) - a(25)
If CInt(a(10) / 2) = a(10) / 2 Then GoTo 100                           'a(10) odd
If a(10) < a1(m1) Or a(10) > a1(m2) Then GoTo 100:
If b1(a(10)) = 0 Then GoTo 100
If b(a(10)) = 0 Then b(a(10)) = a(10): c(10) = a(10) Else GoTo 100

a(6) = 0.4 * s1 - a(10)
If a(6) < a1(m1) Or a(6) > a1(m2) Then GoTo 60:
If b1(a(6)) = 0 Then GoTo 60
If b(a(6)) = 0 Then b(a(6)) = a(6): c(6) = a(6) Else GoTo 60

GoSub 2700              'Complete Border
If fl1 = 0 Then GoTo 5  'No Border Found

GoSub 800: If fl1 = 0 Then GoTo 5

n9 = n9 + 1: GoSub 660  'Print results (squares)

Erase b, c: GoTo 500    'Print only first square

5
b(c(6)) = 0: c(6) = 0
60  b(c(10)) = 0: c(10) = 0
100 b(c(11)) = 0: c(11) = 0
110 b(c(15)) = 0: c(15) = 0
150 Next j15

b(c(16)) = 0: c(16) = 0
160 b(c(20)) = 0: c(20) = 0
200 Next j20

b(c(2)) = 0: c(2) = 0
20  b(c(5)) = 0: c(5) = 0
50  b(c(21)) = 0: c(21) = 0
210 b(c(22)) = 0: c(22) = 0
220 Next j22

b(c(3)) = 0: c(3) = 0
30  b(c(23)) = 0: c(23) = 0
230 Next j23

b(c(4)) = 0: c(4) = 0
40  b(c(24)) = 0: c(24) = 0
240 Next j24

b(c(1)) = 0: c(1) = 0
10  b(c(25)) = 0: c(25) = 0
250 Next j25

Erase b, c
500 Next j100

t2 = Timer

t10 = Str(t2 - t1) + " sec., " + Str(n9) + " Solutions for sum" + Str(s1)
y = MsgBox(t10, 0, "Routine MgcSqr7b")

End

660 n2 = n2 + 1
If n2 = 5 Then
n2 = 1: k1 = k1 + 8: k2 = 1
Else
If n9 > 1 Then k2 = k2 + 8
End If

Cells(k1, k2 + 1).Select
Cells(k1, k2 + 1).Font.Color = -4165632
Cells(k1, k2 + 1).Value = n9

i3 = 0
For i1 = 1 To 7
For i2 = 1 To 7
i3 = i3 + 1
Cells(k1 + i1, k2 + i2).Value = a7(i3)
Next i2
Next i1

Return

'   Exclude solutions with identical numbers

800 fl1 = 1
For j1 = 1 To 7
a2 = a(j1): If a2 = 0 Then GoTo 810
For j2 = (1 + j1) To 7
If a2 = a(j2) Then fl1 = 0: Return
Next j2
810 Next j1
Return

'    Complete Border

2700 fl1 = 1: s2 = 50: s7 = 175
Erase a7, c7

a7(9) = a(1):   a7(10) = a(2):  a7(11) = a(3):  a7(12) = a(4):  a7(13) = a(5):
a7(16) = a(6):  a7(17) = a(7):  a7(18) = a(8):  a7(19) = a(9):  a7(20) = a(10):
a7(23) = a(11): a7(24) = a(12): a7(25) = a(13): a7(26) = a(14): a7(27) = a(15):
a7(30) = a(16): a7(31) = a(17): a7(32) = a(18): a7(33) = a(19): a7(34) = a(20):
a7(37) = a(21): a7(38) = a(22): a7(39) = a(23): a7(40) = a(24): a7(41) = a(25):

For jj49 = m1 + 1 To m2 - 1 Step 2                                          'a7(49) even
If b(a1(jj49)) = 0 Then b(a1(jj49)) = a1(jj49): c7(49) = a1(jj49) Else GoTo 2490
a7(49) = a1(jj49)

a7(1) = s2 - a7(49): If b(a7(1)) = 0 Then b(a7(1)) = a7(1): c7(1) = a7(1) Else GoTo 2010

For jj48 = m1 + 1 To m2 - 1 Step 2                                          'a7(48) even
If b(a1(jj48)) = 0 Then b(a1(jj48)) = a1(jj48): c7(48) = a1(jj48) Else GoTo 2480
a7(48) = a1(jj48)

a7(6) = s2 - a7(48): If b(a7(6)) = 0 Then b(a7(6)) = a7(6): c7(6) = a7(6) Else GoTo 2060

For jj47 = m1 + 1 To m2 - 1 Step 2                                          'a7(47) even
If b(a1(jj47)) = 0 Then b(a1(jj47)) = a1(jj47): c7(47) = a1(jj47) Else GoTo 2470
a7(47) = a1(jj47)

a7(5) = s2 - a7(47): If b(a7(5)) = 0 Then b(a7(5)) = a7(5): c7(5) = a7(5) Else GoTo 2050

For jj46 = m1 To m2 Step 2                                                  'a7(46) odd
If b(a1(jj46)) = 0 Then b(a1(jj46)) = a1(jj46): c7(46) = a1(jj46) Else GoTo 2460
a7(46) = a1(jj46)

a7(4) = s2 - a7(46): If b(a7(4)) = 0 Then b(a7(4)) = a7(4): c7(4) = a7(4) Else GoTo 2040

For jj45 = m1 + 1 To m2 - 1 Step 2                                          'a7(45) even
If b(a1(jj45)) = 0 Then b(a1(jj45)) = a1(jj45): c7(45) = a1(jj45) Else GoTo 2450
a7(45) = a1(jj45)

a7(3) = s2 - a7(45): If b(a7(3)) = 0 Then b(a7(3)) = a7(3): c7(3) = a7(3) Else GoTo 2030

For jj44 = m1 + 1 To m2 - 1 Step 2                                          'a7(44) even
If b(a1(jj44)) = 0 Then b(a1(jj44)) = a1(jj44): c7(44) = a1(jj44) Else GoTo 2440
a7(44) = a1(jj44)

a7(43) = s7 - a7(44) - a7(45) - a7(46) - a7(47) - a7(48) - a7(49)
If CInt(a7(43) / 2) <> a7(43) / 2 Then GoTo 2430                            'a7(43) even
If a7(43) < a1(m1) Or a7(43) > a1(m2) Then GoTo 2430
If b1(a7(43)) = 0 Then GoTo 2430
If b(a7(43)) = 0 Then b(a7(43)) = a7(43): c7(43) = a7(43) Else GoTo 2430

a7(7) = s2 - a7(43): If b(a7(7)) = 0 Then b(a7(7)) = a7(7): c7(7) = a7(7) Else GoTo 2070
a7(2) = s2 - a7(44): If b(a7(2)) = 0 Then b(a7(2)) = a7(2): c7(2) = a7(2) Else GoTo 2020

For jj42 = m1 + 1 To m2 - 1 Step 2                                          'a7(42) even
If b(a1(jj42)) = 0 Then b(a1(jj42)) = a1(jj42): c7(42) = a1(jj42) Else GoTo 2420
a7(42) = a1(jj42)

a7(36) = s2 - a7(42): If b(a7(36)) = 0 Then b(a7(36)) = a7(36): c7(36) = a7(36) Else GoTo 2360

For jj35 = m1 + 1 To m2 - 1 Step 2                                          'a7(35) even
If b(a1(jj35)) = 0 Then b(a1(jj35)) = a1(jj35): c7(35) = a1(jj35) Else GoTo 2350
a7(35) = a1(jj35)

a7(29) = s2 - a7(35): If b(a7(29)) = 0 Then b(a7(29)) = a7(29): c7(29) = a7(29) Else GoTo 2290

For jj28 = m1 To m2 Step 2                                                  'a7(28) odd
If b(a1(jj28)) = 0 Then b(a1(jj28)) = a1(jj28): c7(28) = a1(jj28) Else GoTo 2280
a7(28) = a1(jj28)

a7(22) = s2 - a7(28): If b(a7(22)) = 0 Then b(a7(22)) = a7(22): c7(22) = a7(22) Else GoTo 2220

For jj21 = m1 + 1 To m2 - 1 Step 2                                          'a7(21) even
If b(a1(jj21)) = 0 Then b(a1(jj21)) = a1(jj21): c7(21) = a1(jj21) Else GoTo 2210
a7(21) = a1(jj21)

a7(15) = s2 - a7(21): If b(a7(15)) = 0 Then b(a7(15)) = a7(15): c7(15) = a7(15) Else GoTo 2150

a7(14) = -3 * s2 / 2 + a7(15) + a7(22) + a7(29) + a7(36) + a7(43) - a7(49)
If CInt(a7(14) / 2) <> a7(14) / 2 Then GoTo 2140
If a7(14) < a1(m1) Or a7(14) > a1(m2) Then GoTo 2140
If b1(a7(14)) = 0 Then GoTo 2140
If b(a7(14)) = 0 Then b(a7(14)) = a7(14): c7(14) = a7(14) Else GoTo 2140

a7(8) = s2 - a7(14): If b(a7(8)) = 0 Then b(a7(8)) = a7(8): c7(8) = a7(8) Else GoTo 2080

Return

2085
b(c7(8)) = 0: c7(8) = 0
2080 b(c7(14)) = 0: c7(14) = 0
2140 b(c7(15)) = 0: c7(15) = 0
2150 b(c7(21)) = 0: c7(21) = 0
2210 Next jj21

b(c7(22)) = 0: c7(22) = 0
2220 b(c7(28)) = 0: c7(28) = 0
2280 Next jj28

b(c7(29)) = 0: c7(29) = 0
2290 b(c7(35)) = 0: c7(35) = 0
2350 Next jj35

b(c7(36)) = 0: c7(36) = 0
2360 b(c7(42)) = 0: c7(42) = 0
2420 Next jj42

b(c7(2)) = 0: c7(2) = 0
2020 b(c7(7)) = 0: c7(7) = 0
2070 b(c7(43)) = 0: c7(43) = 0
2430 b(c7(44)) = 0: c7(44) = 0
2440 Next jj44

b(c7(3)) = 0: c7(3) = 0
2030 b(c7(45)) = 0: c7(45) = 0
2450 Next jj45

b(c7(4)) = 0: c7(4) = 0
2040 b(c7(46)) = 0: c7(46) = 0
2460 Next jj46

b(c7(5)) = 0: c7(5) = 0
2050 b(c7(47)) = 0: c7(47) = 0
2470 Next jj47

b(c7(6)) = 0: c7(6) = 0
2060 b(c7(48)) = 0: c7(48) = 0
2480 Next jj48

b(c7(1)) = 0: c7(1) = 0
2010 b(c7(49)) = 0: c7(49) = 0
2490 Next jj49

fl1 = 0
Return

End Sub
```