%I #9 Aug 15 2019 16:50:43
%S 0,0,1,2,12,64,475,5036,80947,2010328,76115143
%N Number of connected graphs on n nodes with chromatic number 3.
%H Keith M. Briggs, <a href="http://keithbriggs.info/cgt.html">Combinatorial Graph Theory</a>
%Y A diagonal of triangle in A126736.
%K nonn
%O 1,4
%A _N. J. A. Sloane_, Feb 16 2007
%E a(11) from _Michael Sollami_, Jan 29 2012