' Generates Concentric Magic Squares of order 5

' Tested with Office 2007 under Windows 7

```Sub MgcSqr5d()

Dim a(25), b(25), c(25)

y = MsgBox("Locked", vbCritical, "Routine MgcSqr5d")
End

n2 = 0: n3 = 0: n9 = 0
m1 = 1: m2 = 25: s1 = 65

'   Generate data

t1 = Timer

For j25 = m1 To m2                                          'a(25)
If b(j25) = 0 Then b(j25) = j25: c(25) = j25 Else GoTo 250
a(25) = j25
For j24 = m1 To m2                                          'a(24)
If b(j24) = 0 Then b(j24) = j24: c(24) = j24 Else GoTo 240
a(24) = j24
For j23 = m1 To m2                                          'a(23)
If b(j23) = 0 Then b(j23) = j23: c(23) = j23 Else GoTo 230
a(23) = j23
For j22 = m1 To m2                                          'a(22)
If b(j22) = 0 Then b(j22) = j22: c(22) = j22 Else GoTo 220
a(22) = j22

a(21) = 65 - a(22) - a(23) - a(24) - a(25): If a(21) <= 0 Or a(21) > 25 Then GoTo 210
If b(a(21)) = 0 Then b(a(21)) = a(21): c(21) = a(21) Else GoTo 210

For j20 = m1 To m2                                          'a(20)
If b(j20) = 0 Then b(j20) = j20: c(20) = j20 Else GoTo 200
a(20) = j20
For j19 = 10 To 10                                          'a(19)
If b(j19) = 0 Then b(j19) = j19: c(19) = j19 Else GoTo 190
a(19) = j19
For j18 = 15 To 15                                          'a(18)
If b(j18) = 0 Then b(j18) = j18: c(18) = j18 Else GoTo 180
a(18) = j18

a(17) = 39 - a(18) - a(19): If a(17) <= 0 Or a(17) > 25 Then GoTo 170
If b(a(17)) = 0 Then b(a(17)) = a(17): c(17) = a(17) Else GoTo 170
a(16) = 26 - a(20): If a(16) <= 0 Or a(16) > 25 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                                          'a(15)
If b(j15) = 0 Then b(j15) = j15: c(15) = j15 Else GoTo 150
a(15) = j15

a(14) = 52 - a(18) - 2 * a(19): If a(14) <= 0 Or a(14) > 25 Then GoTo 140
a(13) = 13
a(12) = -26 + a(18) + 2 * a(19): If a(12) <= 0 Or a(12) > 25 Then GoTo 140
a(11) = 26 - a(15): If a(11) <= 0 Or a(11) > 25 Then GoTo 140
a(10) = 39 - a(15) - a(20) + a(21) - a(25): If a(10) <= 0 Or a(10) > 25 Then GoTo 140
a(9) = -13 + a(18) + a(19): If a(9) <= 0 Or a(9) > 25 Then GoTo 140
a(8) = 26 - a(18): If a(8) <= 0 Or a(8) > 25 Then GoTo 140
a(7) = 26 - a(19): If a(7) <= 0 Or a(7) > 25 Then GoTo 140
a(6) = -13 + a(15) + a(20) - a(21) + a(25): If a(6) <= 0 Or a(6) > 25 Then GoTo 140
a(5) = 26 - a(21): If a(5) <= 0 Or a(5) > 25 Then GoTo 140
a(4) = 26 - a(24): If a(4) <= 0 Or a(4) > 25 Then GoTo 140
a(3) = 26 - a(23): If a(3) <= 0 Or a(3) > 25 Then GoTo 140
a(2) = 26 - a(22): If a(2) <= 0 Or a(2) > 25 Then GoTo 140
a(1) = 26 - a(25): If a(1) <= 0 Or a(1) > 25 Then GoTo 140

'                          Exclude solutions with identical numbers

GoSub 800: If fl1 = 0 Then GoTo 140

n9 = n9 + 1
GoSub 650 'Print results (squares)
'                          GoSub 640 'Print results (selected numbers)

140 b(c(15)) = 0: c(15) = 0
150 Next j15
b(c(16)) = 0: c(16) = 0
160 b(c(17)) = 0: c(17) = 0
170 b(c(18)) = 0: c(18) = 0
180 Next j18
b(c(19)) = 0: c(19) = 0
190 Next j19
b(c(20)) = 0: c(20) = 0
200 Next j20
b(c(21)) = 0: c(21) = 0
210 b(c(22)) = 0: c(22) = 0
220 Next j22
b(c(23)) = 0: c(23) = 0
230 Next j23
b(c(24)) = 0: c(24) = 0
240 Next j24
b(c(25)) = 0: c(25) = 0
250 Next j25

t2 = Timer

t10 = Str(t2 - t1) + " sec., " + Str(n9) + " Solutions for sum" + Str(s1)
y = MsgBox(t10, 0, "Routine MgcSqr5d")

End

'   Print results (selected numbers)

640 For i1 = 1 To 25
Cells(n9, i1).Value = a(i1)
Next i1

Return

'   Print results (squares)

650 n2 = n2 + 1
If n2 = 5 Then
n2 = 1: k1 = k1 + 6: k2 = 0
Else
If n9 > 1 Then k2 = k2 + 6
End If

Cells(k1 + 1, k2 + 1).Select

i3 = 0
For i1 = 1 To 5
For i2 = 1 To 5
i3 = i3 + 1
Cells(k1 + i1, k2 + i2).Value = a(i3)
Next i2
Next i1

Return

'   Exclude solutions with identical numbers

800 fl1 = 1
For j1 = 1 To 25
a2 = a(j1)
For j2 = (1 + j1) To 25
If a2 = a(j2) Then fl1 = 0: GoTo 850
Next j2
Next j1
850 Return

End Sub
```