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 A053418 #16 Nov 20 2023 04:19:36 %S A053418 1,1,5,17,80,365,1981,11222,69511,455663,3169244,23170347,177513359, %T A053418 1418920570,11798710013,101778754655,908722427531,8380602471646, %U A053418 79692654473866,780142956502644,7851084073063731,81120767066417308 %N A053418 Number of unlabeled directed graphs with n arcs and no isolated vertices. %H A053418 Andrew Howroyd, <a href="/A053418/b053418.txt">Table of n, a(n) for n = 0..50</a> %F A053418 Euler transform of A053454. - _Andrew Howroyd_, Jan 28 2022 %Y A053418 The labeled version is A121252. %Y A053418 Column sums of A350908. %Y A053418 Cf. A000273, A000664, A053454, A053598 (by # of nodes). %K A053418 nonn %O A053418 0,3 %A A053418 _Vladeta Jovovic_, Jan 10 2000 %E A053418 Edited and extended by _Max Alekseyev_, Sep 18 2009