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 A261006 #19 Nov 27 2023 07:57:05 %S A261006 1,1,1,3,14,157,15942,489980450,1392195547909966848, %T A261006 789204635842035012967539870068113408 %N A261006 Number of unlabeled connected simplicial complexes with n nodes. %C A261006 Inverse Euler transform of A261005 (omitting the a(0) term from A261005). %C A261006 a(0) could equally well be taken to be 0. %D A261006 Benoît Jubin, Posting to Sequence Fans Mailing List, Aug 12 2015 %H A261006 Greg Huber, <a href="/A048143/a048143.pdf">Letters to N. J. A. Sloane, May 1983</a> [Annotated, corrected, scanned copy] %H A261006 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a> %Y A261006 Cf. A261005, A006602. %K A261006 nonn,more,hard %O A261006 0,4 %A A261006 _N. J. A. Sloane_, Aug 13 2015 %E A261006 a(8)-a(9) from _Dmitry I. Ignatov_, Nov 26 2023