A297537 Number of maximum independent vertex sets in the n-triangular honeycomb grid graph.

1, 1, 8, 9, 1, 125, 196, 1, 2744, 6084, 1, 74088, 219024, 1, 2299968, 8450649, 1, 78953589, 338265664, 1, 2924207000, 13840346025, 1, 114933031928, 574510941225, 1, 4738245926336, 24093764931600, 1, 203152294091656

Offset

1,3

Links

Table of n, a(n) for n=1..30.

Eric Weisstein's World of Mathematics, Maximum Independent Vertex Set

Formula

a(3n) = A033536(n+1) = CatalanNumber(n+1)^3

a(3n-1) = 1

a(3n-2) = A244506(n).

Crossrefs

Cf. A033536 (cubes of Catalan numbers).

Cf. A244506 (maximum independent vertex sets for mod(n,3) = 1).

Sequence in context: A053463 A073636 A113521 * A030167 A010767 A334751

Adjacent sequences: A297534 A297535 A297536 * A297538 A297539 A297540

Keyword

nonn

Author

Eric W. Weisstein, Dec 31 2017

Status

approved