Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #9 Apr 23 2018 14:25:37
%S 1,1,1,5,97,6739,1611097,1295101469,3449859538455,30155591559236245,
%T 859063676925680110319,79361177641450830904290293
%N Chromatic invariant of the n-triangular grid graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ChromaticInvariant.html">Chromatic Invariant</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TriangularGridGraph.html">Triangular Grid Graph</a>
%Y Cf. A182283, A182797, A193283.
%K nonn,more
%O 0,4
%A _Eric W. Weisstein_, Nov 16 2017
%E a(8)-a(11) from _Andrew Howroyd_, Apr 23 2018