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 A136930 #7 Apr 12 2024 09:51:26 %S A136930 0,6,60,600,6000,60000,66076,600000,660760,6000000,6607600,60000000, %T A136930 60003706,60036706,66036076,66066376,66076000,600000000,600037060, %U A136930 600306344,600367060,600373006,606336074,660360760,660663760,660760000,660760474,6000000000,6000036706,6000370600,6000637006,6003063440,6003670600,6003730060 %N A136930 Numbers k such that k and k^2 use only the digits 0, 3, 4, 6 and 7. %C A136930 Generated with DrScheme. %C A136930 See also A058429-A058430. - _M. F. Hasler_, Jan 24 2008 %H A136930 Jonathan Wellons, <a href="/A136930/b136930.txt">Table of n, a(n) for n = 1..181</a> %H A136930 J. Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived] %e A136930 660760703770306^2 = 436604707647030077763607333636. %K A136930 base,nonn %O A136930 1,2 %A A136930 Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008