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 A091478 #10 Feb 14 2023 20:56:12 %S A091478 1,1,1,1,1,3,6,6,1,6,30,120,360,720,720,1,10,90,720,5040,30240,151200, %T A091478 604800,1814400,3628800,3628800,1,15,210,2730,32760,360360,3603600, %U A091478 32432400,259459200,1816214400,10897286400,54486432000,217945728000,653837184000,1307674368000,1307674368000 %N A091478 Table of graphs with n (>=0) nodes and k (>=0) edges. Each type of object labeled from its own label set. %D A091478 F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 114 (2.4.44). %F A091478 a(n, k) = k!*binomial(binomial(n, 2), k). %e A091478 1; %e A091478 1; %e A091478 1, 1; %e A091478 1, 3, 6, 6; %e A091478 1, 6, 30, 120, 360, 720, 720; %e A091478 ... %Y A091478 Row sums: A091479. %Y A091478 Row lengths: A000124(n-1) for n>=1. %Y A091478 Columns 0-2: A000012, A000217(n-1), A033487(n-2). %Y A091478 a(n,A000217(n-1)) = A052295(n-1). %Y A091478 Cf. A006125, A008406. %K A091478 nonn,tabf %O A091478 0,6 %A A091478 _Christian G. Bower_, Jan 13 2004 %E A091478 T(0,0)=1 prepended by _Alois P. Heinz_, Feb 14 2023