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A137003
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Numbers k such that k and k^2 use only the digits 1, 2, 5 and 6.
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1
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1, 5, 11, 15, 16, 25, 125, 511, 515, 516, 1125, 2261, 5125, 12511, 12515, 25525, 51211, 125125, 5162515, 51626211, 125162515, 5162525125
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OFFSET
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1,2
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COMMENTS
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Generated with DrScheme.
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LINKS
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EXAMPLE
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5162525125^2 = 26651665666256265625.
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MATHEMATICA
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okQ[n_]:=With[{idn=IntegerDigits[n^2]}, And@@Table[MemberQ[{1, 2, 5, 6}, idn[[i]]], {i, Length[idn]}]]; Flatten[Table[Select[ FromDigits/@ Tuples[{1, 2, 5, 6}, k], okQ], {k, 10}]] (* Harvey P. Dale, Jul 07 2012 *)
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CROSSREFS
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KEYWORD
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base,nonn,more
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AUTHOR
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Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
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STATUS
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approved
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