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 A262591 #9 Oct 19 2023 08:48:11 %S A262591 0,0,4,16,60,208,726,2568,9196,33286,121572,447392,1657006,6170928, %T A262591 23091220,86767014,327235608,1238188768,4698767638 %N A262591 Sets with a congruence property. %H A262591 Alexander Rosa and Štefan Znám, <a href="/A002703/a002703.pdf">A combinatorial problem in the theory of congruences (Russian with English summary)</a>, Mat.-Fys. Casopis Sloven. Akad. Vied 15 1965 49-59. [Annotated scanned copy.] %H A262591 Alexander Rosa and Štefan Znám, <a href="/A002703/a002703_1.pdf">A remark on a combinatorial problem (Russian with English summary)</a>, Mat.-Fyz. Casopis Sloven. Akad. Vied 15 1965 313-316. [Annotated scanned copy] See Table 1. %F A262591 See Maple code in A002705. %K A262591 nonn %O A262591 3,3 %A A262591 _R. J. Mathar_, Oct 21 2015