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 A046751 #24 Apr 24 2021 03:31:58 %S A046751 1,0,1,1,0,0,2,2,1,1,0,0,0,3,5,5,4,2,1,1,0,0,0,0,6,13,19,22,20,14,9,5, %T A046751 2,1,1,0,0,0,0,0,11,33,67,107,132,138,126,95,64,40,21,10,5,2,1,1,0,0, %U A046751 0,0,0,0,23,89,236,486,814,1169,1454,1579,1515,1290,970,658,400,220,114 %N A046751 Triangle read by rows of number of connected graphs with n nodes and k edges (n >= 2, 1 <= k <= n(n-1)/2). %H A046751 G. A. Baker et al., <a href="http://dx.doi.org/10.1103/PhysRev.164.800">High-temperature expansions for the spin-1/2 Heisenberg model</a>, Phys. Rev., 164 (1967), 800-817. %H A046751 Gordon Royle, <a href="http://staffhome.ecm.uwa.edu.au/~00013890/remote/graphs/">Small graphs</a> %H A046751 Peter Steinbach, <a href="/A000088/a000088_17.pdf">Field Guide to Simple Graphs, Volume 1</a>, Part 17 (For Volumes 1, 2, 3, 4 of this book see A000088, A008406, A000055, A000664, respectively.) %e A046751 1; %e A046751 0,1,1; %e A046751 0,0,2,2,1, 1; %e A046751 0,0,0,3,5, 5, 4, 2, 1, 1; %e A046751 0,0,0,0,6,13,19,22, 20, 14, 9, 5, 2, 1, 1; %e A046751 0,0,0,0,0,11,33,67,107,132,138,126,95,64,40,21,10,5,2,1,1; %e A046751 [ the 4th row giving the numbers of connected graphs with 4 nodes and from 1 to 10 edges ]. %Y A046751 See A054924, which is the main entry for this triangle. %Y A046751 Cf. A002905, A008406, A046742, A054923, A054924. %K A046751 nonn,easy,nice,tabf %O A046751 2,7 %A A046751 _N. J. A. Sloane_ %E A046751 More terms from _Vladeta Jovovic_, Apr 21 2000