A137094 Numbers k such that k and k^2 use only the digits 2, 4, 5, 6 and 7.

2, 5, 24, 25, 26, 65, 74, 75, 76, 275, 474, 475, 476, 524, 525, 526, 665, 674, 675, 725, 2574, 2725, 2765, 4762, 6524, 6525, 6665, 6674, 6675, 6725, 6742, 6762, 6765, 7242, 7465, 7525, 27525, 47725, 52465, 52675, 66524, 66525, 66665, 66674, 66675, 66725, 66765, 67426, 67574, 72426, 72475, 72576, 74475, 74476, 75674, 254275, 254475, 255475, 256266

Offset: 1

Author

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

Keywords

• base
• nonn

Comments

Generated with DrScheme.

Examples

			752745425474262^2 = 566625675572427726727624444644.
		

Links

• Jonathan Wellons, Table of n, a(n) for n = 1..837
• J. Wellons, Tables of Shared Digits [archived]

Programs

Mathematica

Module[{c={2,4,5,6,7},nn=6},Select[Flatten[Table[FromDigits/@Tuples[c,n],{n,nn}]],SubsetQ[c,IntegerDigits[#^2]]&]] (* Harvey P. Dale, Oct 03 2019 *)