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

Author

Eric W. Weisstein, Aug 09 2017

Keywords

• nonn

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

Crossrefs

Cf. A287062.

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)

Extensions

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