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 A350490 #7 Jan 09 2022 22:21:53 %S A350490 1,1,2,5,15,50,191,795,3625,17781,93319,519732,3056185,18880345, %T A350490 122066437,823118881,5772473719,41995743085,316258151517, %U A350490 2460542117337,19743544526463,163138014893817,1386173917051704,12096681529032989,108293699332498981 %N A350490 Number of unlabeled acyclic digraphs with n arcs and a global source. %H A350490 Andrew Howroyd, <a href="/A350490/b350490.txt">Table of n, a(n) for n = 0..40</a> %o A350490 (PARI) A350490seq(20) \\ See PARI link in A122078 for program code. %Y A350490 Column sums of A350488. %Y A350490 Cf. A122078, A350415, A350451, A350492. %K A350490 nonn %O A350490 0,3 %A A350490 _Andrew Howroyd_, Jan 08 2022