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%I #24 Apr 24 2021 03:31:58
%S 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 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 0,0,0,0,23,89,236,486,814,1169,1454,1579,1515,1290,970,658,400,220,114
%N Triangle read by rows of number of connected graphs with n nodes and k edges (n >= 2, 1 <= k <= n(n-1)/2).
%H 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 Gordon Royle, <a href="http://staffhome.ecm.uwa.edu.au/~00013890/remote/graphs/">Small graphs</a>
%H 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 1;
%e 0,1,1;
%e 0,0,2,2,1, 1;
%e 0,0,0,3,5, 5, 4, 2, 1, 1;
%e 0,0,0,0,6,13,19,22, 20, 14, 9, 5, 2, 1, 1;
%e 0,0,0,0,0,11,33,67,107,132,138,126,95,64,40,21,10,5,2,1,1;
%e [ the 4th row giving the numbers of connected graphs with 4 nodes and from 1 to 10 edges ].
%Y See A054924, which is the main entry for this triangle.
%Y Cf. A002905, A008406, A046742, A054923, A054924.
%K nonn,easy,nice,tabf
%O 2,7
%A _N. J. A. Sloane_
%E More terms from _Vladeta Jovovic_, Apr 21 2000
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