A137003 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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