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 A137066 #27 Apr 12 2024 18:14:39 %S A137066 2,5,235,2335,23335,233335,2333335,2354235,23333335,233333335, %T A137066 2333333335,2333524235,23333333335,23333524235,233333333335, %U A137066 2333333333335,23333333333335,233333333333335,2333333333333335,23333333333333335,233333333333333335 %N A137066 Numbers k such that k and k^2 use only the digits 2, 3, 4 and 5. %C A137066 Generated with DrScheme. %C A137066 Contains 2*10^m + (10^m-1)/3 + 2 for m >= 2. Are these all the terms > 23333524235? There are no others with up to 25 digits. - _Robert Israel_, Jul 02 2018 %C A137066 There are no others than those of that form with up to 35 digits. - _Michael S. Branicky_, May 25 2021 %H A137066 Jonathan Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]. %e A137066 23333524235^2 = 544453353225332335225. %o A137066 (PARI) isokd(x) = (x < 2) || (x > 5); %o A137066 isok(n) = !#select(x->isokd(x), digits(n)) && !#select(x->isokd(x), digits(n^2)); \\ _Michel Marcus_, Jul 02 2018 %o A137066 (Python) # uses auptod in A137110 %o A137066 print(auptod(16, only="2345")) # _Michael S. Branicky_, May 25 2021 %Y A137066 Cf. A137110. %K A137066 base,nonn %O A137066 1,1 %A A137066 Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008