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 A361589 #5 Mar 16 2023 19:46:14 %S A361589 1,0,1,4,25,271,5682,237684,20042357,3404651985,1162523674892, %T A361589 796395726736678,1093229314594543016,3004753338859186373234, %U A361589 16527845763725396055765240,181891586856152393087373330332,4004313490358484085907684748704180,176328671349936542115174881107633828418 %N A361589 Number of acyclic digraphs on n unlabeled nodes without isolated nodes. %F A361589 a(n) = A003087(n) - A003087(n-1) for n >= 1. %o A361589 (PARI) A361589seq(16) \\ See PARI link in A350794 for program code. %Y A361589 Row sums of A361588. %Y A361589 Cf. A003087, A350794. %K A361589 nonn %O A361589 0,4 %A A361589 _Andrew Howroyd_, Mar 16 2023