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 A020562 #20 Apr 26 2019 08:03:59
%S A020562 1,1,3,17,152,1933,32608,695657,18148533,564860131,20581455139,
%T A020562 864802010595,41392831046804,2233799248861031,134737655762330602,
%U A020562 9015762313899965851,664889968074287179739
%N A020562 Number of cyclic multigraphs on n labeled edges (without loops).
%H A020562 G. Labelle, <a href="https://doi.org/10.1016/S0012-365X(99)00265-4">Counting enriched multigraphs according to the number of their edges (or arcs)</a>, Discrete Math., 217 (2000), 237-248.
%H A020562 G. Paquin, <a href="/A038205/a038205.pdf">Dénombrement de multigraphes enrichis</a>, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004. [Cached copy, with permission]
%F A020562 a(n) = Sum_{k=0..n} (-1)^(n-k)*Stirling1(n, k)*A014500(k). - _Sean A. Irvine_, Apr 25 2019
%Y A020562 Cf. A014500.
%K A020562 nonn
%O A020562 0,3
%A A020562 Gilbert Labelle (gilbert(AT)lacim.uqam.ca), _Simon Plouffe_