A287204 Number of independent vertex sets and vertex covers in the n-triangular honeycomb acute knight graph.

2, 8, 27, 144, 1331, 13824, 208575, 4741632, 140608000, 5870657088, 350253538649, 28635764824584, 3270761581689147, 524882236329014264, 117025388905265182783, 36405238728128712859232, 15833111238624255435917875, 9599917578598545475054063616

Offset

1,1

Comments

Also row sums of A244500.

Links

Table of n, a(n) for n=1..18.

Stan Wagon, Graph Theory Problems from Hexagonal and Traditional Chess, The College Mathematics Journal, Vol. 45, No. 4, September 2014, pp. 278-287.

Eric Weisstein's World of Mathematics, Independent Vertex Set

Eric Weisstein's World of Mathematics, Vertex Cover

Crossrefs

Cf. A244500 (coefficients of independence polynomial of triangular honeycomb acute knight graphs).

Cf. A287195, A289902, A287230, A287229, A027740.

Sequence in context: A150712 A150713 A276940 * A299640 A197932 A170871

Adjacent sequences: A287201 A287202 A287203 * A287205 A287206 A287207

Keyword

nonn

Author

Eric W. Weisstein, May 21 2017

Extensions

a(15)-a(18) from Andrew Howroyd, Jul 17 2017

Status

approved