The digits of 5^3=125, can be permuted to form 8^3=512.
Find the smallest cube whose digits can be permuted to produce
two other cubes.
41063625 is the smallest such cube, from
41063625 56623104 66430125
56623104 66430125 41063625
66430125 41063625 56623104
The three numbers are the cubes of 345, 384 and 405.
These are the first three rows of output from
DefDbl A-Z
Dim crlf$, hist(90)
Private Sub Form_Load()
Form1.Visible = True
Text1.Text = ""
crlf = Chr$(13) + Chr$(10)
For n = 3 To 9999
DoEvents
cubect = 0
cube = n * n * n
s$ = LTrim(Str(cube)): h$ = s
Do
permute s
If s = h Then Exit Do
v = Val(s)
cr = Int(v ^ (1 / 3) + 0.5)
If cr * cr * cr = v And Left(s, 1) <> "0" Then cubect = cubect + 1: hist(cubect) = v
Loop
If cubect > 1 Then
Text1.Text = Text1.Text & h & " "
For i = 1 To cubect
Text1.Text = Text1.Text & Str(hist(i))
Next
Text1.Text = Text1.Text & crlf
End If
Next
Text1.Text = Text1.Text & crlf & " done"
End Sub
The program finds further values:
Filtering out duplicates (as each set is listed for each of its members):
1003003001 1030301000 1331000000
1006012008 1061208000 8012006001 8120601000
1086373952 1375036928 5097328361
1287913472 1897413272 3877292411
2062933417 3029741623 9274236301
3595640768 6740558369 7066834559
5204699837 6804992375 8402569937
The program was stopped before terminating. The list includes 1006012008 = 1002^3, which has 3 permutations that are cubes and are in fact cubes of permutations of 1002.
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Posted by Charlie
on 2015-10-14 10:45:14 |