A290708 Number of irredundant sets in the (2 n)-crossed prism graph.

9, 77, 609, 5221, 44914, 383279, 3267224, 27844845, 237311925, 2022585862, 17238412156, 146922412111, 1252214688188, 10672581690652, 90962034893584, 775266190295021, 6607566186841867, 56316051804768503, 479979708366734131, 4090849998653543166

Offset

1,1

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Eric Weisstein's World of Mathematics, Crossed Prism Graph

Eric Weisstein's World of Mathematics, Irredundant Set

Formula

From Andrew Howroyd, Aug 10 2017: (Start)

Empirical: a(n) = 9*a(n-1) - 2*a(n-2) - 22*a(n-3) + 23*a(n-4) + 126*a(n-5) - 2*a(n-6) - 184*a(n-7) - 64*a(n-8) for n > 8.

Empirical g.f.: x*(9 - 4*x - 66*x^2 + 92*x^3 + 630*x^4 - 12*x^5 - 1288*x^6 - 512*x^7)/(1 - 9*x + 2*x^2 + 22*x^3 - 23*x^4 - 126*x^5 + 2*x^6 + 184*x^7 + 64*x^8).

(End)

Crossrefs

Cf. A287062.

Sequence in context: A282327 A263471 A266125 * A126631 A190981 A254659

Adjacent sequences: A290705 A290706 A290707 * A290709 A290710 A290711

Keyword

nonn

Author

Eric W. Weisstein, Aug 09 2017

Extensions

a(1) and terms a(7) and beyond from Andrew Howroyd, Aug 10 2017

Status

approved