

A094632


A trace sequence for a Napoleon graph.


1



1, 0, 3, 4, 21, 55, 198, 609, 2021, 6460, 21033, 67859, 219926, 711165, 2302233, 7448804, 24107061, 78008495, 252446598, 816924969, 2643639901, 8554973900, 27684516753, 89588913979, 289915919446, 938187455205, 3036038652273
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OFFSET

0,3


COMMENTS

a(n)=trace(A^n)/6 where A is the adjacency matrix of the graph obtained by constructing external triangles on the sides of a triangle (or equivalently, taking a triangle and its midpoint triangle). A Lucas Jacobsthal product. Compare with A093042.


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CROSSREFS



KEYWORD

easy,nonn


AUTHOR



STATUS

approved



