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 A020563 #20 Apr 26 2019 08:04:06
%S A020563 1,2,9,68,750,11178,213895,5068102,144746329,4880572564,191104219619,
%T A020563 8573780527428,435844228476008,24868815362420244,1579939008182007447,
%U A020563 110981916769308996238,8567134375799509782211
%N A020563 Number of cyclic multigraphs on n labeled edges (with loops).
%H A020563 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 A020563 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 A020563 a(n) = Sum_{k=0..n} (-1)^(n-k)*Stirling1(n, k)*A014501(k). - _Sean A. Irvine_, Apr 25 2019
%Y A020563 Cf. A014501.
%K A020563 nonn
%O A020563 0,2
%A A020563 Gilbert Labelle (gilbert(AT)lacim.uqam.ca), _Simon Plouffe_