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 A052171 #35 Mar 04 2024 15:18:27 %S A052171 1,2,11,52,296,1724,11060,74527,533046,3999187,31412182,257150093, %T A052171 2188063401,19299062896,176059781439,1657961491087,16089088019098, %U A052171 160643776819423,1648068916722737,17351137043998280,187255329043638437,2069426416836401375,23397468305569068113,270406562951254606048,3191908298072118225550,38454691427657997701136 %N A052171 Number of directed multigraphs with loops on an infinite set of nodes containing a total of n arcs. %C A052171 Row sums of A136564, limiting values of A138107. - _Benoit Jubin_, May 13 2008 %C A052171 Euler transform of A137975. - _M. F. Hasler_, Jul 31 2017 %H A052171 Andrew Howroyd, <a href="/A052171/b052171.txt">Table of n, a(n) for n = 0..50</a> %H A052171 Banglei Guan, Ji Zhao, and Laurent Kneip, <a href="https://arxiv.org/abs/2402.18066">Six-Point Method for Multi-Camera Systems with Reduced Solution Space</a>, arXiv:2402.18066 [cs.CV], 2024. See p. 10. %H A052171 J.-C. Novelli, J.-Y. Thibon and N. M. Thiery, <a href="http://nicolas.thiery.name/Preprints/NovelliThibonThiery.2004/NovelliThibonThiery.2004.pdf">Algèbres de Hopf de graphes</a>, C.R. Acad. Sci. Paris (Comptes Rendus Mathématique), 339 (2004), 607-610. %H A052171 Sanjaye Ramgoolam, <a href="https://arxiv.org/abs/1809.07559">Permutation Invariant Gaussian Matrix Models</a>, arXiv:1809.07559 [hep-th], 2018. %F A052171 a(n) = A138107(2*n,n). - _Max Alekseyev_, Oct 17 2017 %Y A052171 Cf. A050535, A007717, A005993, A050927, A050929. %Y A052171 Cf. A104209. Cf. A137975 (connected). %K A052171 nonn %O A052171 0,2 %A A052171 _Vladeta Jovovic_, Jan 26 2000 %E A052171 a(16)-a(25) from _Max Alekseyev_, Jun 21 2011