A297557 Number of maximum independent vertex sets in the n-triangular grid graph.

1, 3, 1, 1, 1, 27, 2, 28, 32, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27, 27, 1, 27

Offset

0,2

Links

Table of n, a(n) for n=0..37.

John Machacek, Unique maximum independent sets in graphs on monomials of a fixed degree, arXiv:2010.11112 [math.CO], 2020-2021. See Theorem 2.1 p. 4.

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, Maximum Independent Vertex Set

Eric Weisstein's World of Mathematics, Triangular Grid Graph

Formula

Conjecture: a(n) = a(n-3) for n >= 12. - Andrew Howroyd, Jan 01 2018

a(3k) = 1 for all k != 2. - John Machacek, May 01 2021

Crossrefs

Cf. A027740, A197564, A239438.

Sequence in context: A347811 A320412 A286591 * A066827 A016467 A342275

Adjacent sequences: A297554 A297555 A297556 * A297558 A297559 A297560

Keyword

nonn,more

Author

Eric W. Weisstein, Dec 31 2017

Extensions

a(11)-a(24) from Andrew Howroyd, Jan 01 2018

a(25)-a(37) from Eric W. Weisstein, Feb 10 2024

Status

approved