This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A137094 #9 Apr 12 2024 09:51:27
%S A137094 2,5,24,25,26,65,74,75,76,275,474,475,476,524,525,526,665,674,675,725,
%T A137094 2574,2725,2765,4762,6524,6525,6665,6674,6675,6725,6742,6762,6765,
%U A137094 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
%N A137094 Numbers k such that k and k^2 use only the digits 2, 4, 5, 6 and 7.
%C A137094 Generated with DrScheme.
%H A137094 Jonathan Wellons, <a href="/A137094/b137094.txt">Table of n, a(n) for n = 1..837</a>
%H A137094 J. Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]
%e A137094 752745425474262^2 = 566625675572427726727624444644.
%t A137094 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 *)
%K A137094 base,nonn
%O A137094 1,1
%A A137094 Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008