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 A004076 #27 Oct 24 2023 19:24:00 %S A004076 0,1,2,0,0,38,124,0,0,12808,72648,0,0,21878816,168870048,0,0, %T A004076 113071735648,1105816948032,0,0,1395701792232832 %N A004076 Number of hooked Skolem sequences of order n. %D A004076 CRC Handbook of Combinatorial Designs, 1996, p. 460. %H A004076 Jeppe Winther Larsen, <a href="https://pdfs.semanticscholar.org/6377/9c279f8e27f5ed46ff6fe5c0624eebe5de7e.pdf">Counting the Skolem sequences using inclusion-exclusion</a>, 2009 %e A004076 For n = 3, there are 2 solutions: 1 1 2 3 2 0 3 and 3 1 1 3 2 0 2. %K A004076 nonn,more %O A004076 1,3 %A A004076 _N. J. A. Sloane_ %E A004076 a(15)-a(18) from Jeppe Winther Larsen (jwl(AT)itu.dk), Oct 12 2009 %E A004076 a(4)-a(18) confirmed, a(3) corrected by _Fausto A. C. Cariboni_, Apr 11 2017 %E A004076 a(19)-a(22) from _Fausto A. C. Cariboni_, Apr 25 2017