A137003 Numbers k such that k and k^2 use only the digits 1, 2, 5 and 6.

1, 5, 11, 15, 16, 25, 125, 511, 515, 516, 1125, 2261, 5125, 12511, 12515, 25525, 51211, 125125, 5162515, 51626211, 125162515, 5162525125

Offset: 1

Author

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Keywords

• base
• nonn
• more

Comments

Generated with DrScheme.

Subsequence of A137004 and A137007. - M. F. Hasler, Jan 24 2008

Examples

			5162525125^2 = 26651665666256265625.
		

Links

• Jonathan Wellons, Tables of Shared Digits [archived]

Programs

Mathematica

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 *)