%I A076322
%S A076322 1,1,2,5,17,81,519,5218,81677
%N A076322 Number of connected 3-colorable (i.e. chromatic number <= 3) simple graphs 
               on n nodes.
%H A076322 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               n-ColorableGraph.html">n-Colorable Graph</a>
%Y A076322 Cf. A005142, A076323, A076324, A076325, A076326, A076327, A076328.
%Y A076322 Sequence in context: A001186 A125282 A020125 this_sequence A098540 A079574 
               A032262
%Y A076322 Adjacent sequences: A076319 A076320 A076321 this_sequence A076323 A076324 
               A076325
%K A076322 nonn,more
%O A076322 1,3
%A A076322 Eric Weisstein (eric(AT)weisstein.com), Oct 06, 2002