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%I #7 Nov 17 2019 01:16:56
%S 0,0,0,0,0,0,0,0,0,0,1,21,826,39889
%N Number of triangle-free graphs g on n nodes for which the chromatic number chi(g) equals r(g) = ceiling((Delta(g) + 1 + omega(g))/2).
%C Here Delta(g) is the maximum node degree of g and omega(g) is the clique number of g (=2 for triangle-free graphs). r(g) is conjectured by Reed to be an upper bound for chi(g) for all graphs.
%C The sequence is of interest as a measure of how frequently the bound is attained. For example, for n=14 there are 467871369 triangle-free graphs.
%D B. Reed, omega, Delta and chi, J Graph Theory 27, 177-212 (1998).
%K nonn
%O 1,12
%A _Keith Briggs_, Jul 26 2006