Сколько комбинаций по 6 цифр можно составить?

вот такой макрос на VBA в excel
Sub ppp()
Cells.ClearContents
For ii1 = 1 To 40
Cells(1, ii1) = ii1
Cells(2, ii1) = 1
If ii1 > 9 Then
Cells(2, ii1) = 2
End If
Next ii1
kk = 3
For ii1 = 1 To 40
For ii2 = ii1 + 1 To 40
For ii3 = ii2 + 1 To 40
If Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) = 6 Then
' òóò âûâîäèì
Cells(kk, 1) = "" & Cells(1, ii1) & Cells(1, ii2) & Cells(1, ii3)
kk = kk + 1
ElseIf Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) < 6 Then
For ii4 = ii3 + 1 To 40
If Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) + Cells(2, ii4) = 6 Then
' òóò âûâîäèì
Cells(kk, 1) = "" & Cells(1, ii1) & Cells(1, ii2) & Cells(1, ii3) & Cells(1, ii4)
kk = kk + 1
ElseIf Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) + Cells(2, ii4) < 6 Then
For ii5 = ii4 + 1 To 40
If Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) + Cells(2, ii4) + Cells(2, ii5) = 6 Then
' òóò âûâîäèì
Cells(kk, 1) = "" & Cells(1, ii1) & Cells(1, ii2) & Cells(1, ii3) & Cells(1, ii4) & Cells(1, ii5)
kk = kk + 1
ElseIf Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) + Cells(2, ii4) + Cells(2, ii5) < 6 Then
For ii6 = ii5 + 1 To 40
If Cells(2, ii1) + Cells(2, ii2) + Cells(2, ii3) + Cells(2, ii4) + Cells(2, ii5) + Cells(2, ii6) = 6 Then
' òóò âûâîäèì
If Not (Cells(1, ii2) - Cells(1, ii1) = 1 And Cells(1, ii3) - Cells(1, ii2) = 1 And Cells(1, ii4) - Cells(1, ii3) = 1 And Cells(1, ii5) - Cells(1, ii4) = 1 And Cells(1, ii6) - Cells(1, ii5) = 1) Then
Cells(kk, 1) = "" & Cells(1, ii1) & Cells(1, ii2) & Cells(1, ii3) & Cells(1, ii4) & Cells(1, ii5) & Cells(1, ii6)
kk = kk + 1
End If
End If
Next ii6
End If
Next ii5
End If
Next ii4
End If
Next ii3
Next ii2
Next ii1
End Sub
выдаст начало картинки:

и конец картинки:

т.е. искомых чисел будет 25221