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 A137116 #18 Apr 12 2024 18:06:51 %S A137116 5,27,77,85,527,727,7227,9777,28277,29585,88277,99277,278527,298827, %T A137116 2788527,2789227,5289227,8875727,9889277,22925527,27797977,29879585, %U A137116 52898827,85298827,88875527,99789227,99988777,278889277,287279585,292898827,297875527,299929585,527252527,528982977,727528527,727825527,727925527,988579585,992587527 %N A137116 Numbers k such that k and k^2 use only the digits 2, 5, 7, 8 and 9. %C A137116 Generated with DrScheme. %H A137116 Michael S. Branicky, <a href="/A137116/b137116.txt">Table of n, a(n) for n = 1..578</a> (through 20 digits; first 180 terms from Jonathan Wellons) %H A137116 Jonathan Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]. %e A137116 727872928279585^2 = 529798999722297889227927772225. %o A137116 (Python) # uses auptod in A137110 %o A137116 print(auptod(16, only="25789")) # _Michael S. Branicky_, May 27 2021 %Y A137116 Cf. A137110, A137117. %K A137116 base,nonn %O A137116 1,1 %A A137116 Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008