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 A004077 #30 Oct 24 2023 07:02:09 %S A004077 2,2,6,22,48,160,636,3556,19488,95872,594320,4459888,32131648, %T A004077 227072544,1875064880,17851780784,165367171136,1506506453568, %U A004077 15540217445728,179708231523680,2034547787823488,22716589497430656 %N A004077 Number of extended Skolem sequences of order n. %D A004077 CRC Handbook of Combinatorial Designs, 1996, p. 460. %H A004077 Jeppe Winther Larsen, <a href="https://pdfs.semanticscholar.org/6377/9c279f8e27f5ed46ff6fe5c0624eebe5de7e.pdf">Counting the Skolem sequences using inclusion-exclusion</a>, 2009 %K A004077 nonn,more %O A004077 1,1 %A A004077 _N. J. A. Sloane_ %E A004077 a(15)-a(18) from Jeppe Winther Larsen (jwl(AT)itu.dk), Oct 12 2009 %E A004077 a(19)-a(21) from _Fausto A. C. Cariboni_, Apr 19 2017 %E A004077 a(22) from _Fausto A. C. Cariboni_, May 07 2017