A137005 Numbers k such that k and k^2 use only the digits 1, 2, 5, 6 and 8.

1, 5, 11, 15, 16, 25, 81, 125, 261, 285, 511, 515, 516, 816, 1125, 1285, 1585, 2261, 2285, 2581, 2585, 5125, 11211, 12511, 12515, 12581, 25525, 25615, 26125, 28615, 28665, 51211, 81125, 81585, 112166, 125125, 158816, 256615, 258125, 261125, 261881, 285515, 515615, 811516, 828665, 1118865, 1585125, 1681125, 2261125, 2285216, 5162515, 5185125

Offset: 1

Author

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

Keywords

• base
• nonn

Comments

Generated with DrScheme.

Examples

			828652861686516^2 = 686665565181252216515856218256.
		

Links

• Jonathan Wellons, Table of n, a(n) for n = 1..435
• J. Wellons, Tables of Shared Digits [archived]

Programs

Mathematica

With[{c={1,2,5,6,8}},Select[Flatten[Table[FromDigits/@Tuples[c,n],{n,7}]],SubsetQ[c,IntegerDigits[#^2]]&]] (* Harvey P. Dale, Apr 16 2015 *)