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

1,2

Comments

Generated with DrScheme.

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

Links

Table of n, a(n) for n=1..22.

Jonathan Wellons, Tables of Shared Digits [archived]

Example

5162525125^2 = 26651665666256265625.

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 *)

Crossrefs

Sequence in context: A137004 A137005 A137006 * A314003 A314004 A296031

Adjacent sequences: A137000 A137001 A137002 * A137004 A137005 A137006

Keyword

base,nonn,more

Author

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

Status

approved