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 A006415 M3705 #17 Apr 05 2021 13:34:05 %S A006415 4,104,1020,6092,26670,94128,283338,754380,1821534,4061200 %N A006415 Number of nonseparable toroidal tree-rooted maps with n + 3 edges and n + 1 vertices. %C A006415 The number of faces is 2. - _Andrew Howroyd_, Apr 05 2021 %D A006415 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006415 T. R. S. Walsh and A. B. Lehman, <a href="http://dx.doi.org/10.1016/0095-8956(75)90050-7">Counting rooted maps by genus. III: Nonseparable maps</a>, J. Combinatorial Theory Ser. B 18 (1975), 222-259. %F A006415 Conjecture: a(n) = 4 * binomial(n + 4, n) + 84 * binomial(n + 4, n - 1) + 456 * binomial(n + 4, n - 2) + 996 * binomial(n + 4, n - 3) + 950 * binomial(n + 4, n - 4) + 330 * binomial(n + 5, n - 5). - _Sean A. Irvine_, Apr 03 2017 %Y A006415 Cf. A006414, A006441. %K A006415 nonn,more %O A006415 0,1 %A A006415 _N. J. A. Sloane_