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

Author

Eric W. Weisstein, Dec 31 2017

Keywords

• nonn

Links

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

Crossrefs

Cf. A033536 (cubes of Catalan numbers).

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

Formula

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

a(3n-1) = 1

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