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 A350415 #14 Jan 09 2022 12:44:11 %S A350415 1,1,3,16,164,3341,138101,11578037,1961162564,668678055847, %T A350415 457751797355605,628137837068751147,1726130748679532455689, %U A350415 9493834992383031007906911,104476428350838383854529661007,2299979227717819421763629684068904 %N A350415 Number of acyclic digraphs on n unlabeled nodes with a global source (or sink). %C A350415 A local source (also called an out-node) is a node whose in-degree is zero. In the case of an acyclic digraph with only one local source, the source is also a global source. %H A350415 Andrew Howroyd, <a href="/A350415/b350415.txt">Table of n, a(n) for n = 1..50</a> %H A350415 Marcel et al., <a href="https://mathoverflow.net/q/395095">Is there a formula for the number of st-dags (DAG with 1 source and 1 sink) with n vertices?</a>, MathOverflow, 2021. %o A350415 (PARI) A350415seq(16) \\ See PARI link in A122078 for program code. %Y A350415 The labeled case is A003025. %Y A350415 Row sums of A350488. %Y A350415 A diagonal of A122078. %Y A350415 Cf. A003087, A345258, A350360. %K A350415 nonn %O A350415 1,3 %A A350415 _Andrew Howroyd_, Dec 29 2021