A308604 Number of (not necessarily maximal) cliques in the n X n fiveleaper graph.

2, 5, 10, 17, 34, 73, 126, 193, 274, 369, 478, 601, 738, 889, 1054, 1233, 1426, 1633, 1854, 2089, 2338, 2601, 2878, 3169, 3474, 3793, 4126, 4473, 4834, 5209, 5598, 6001, 6418, 6849, 7294, 7753, 8226, 8713, 9214, 9729, 10258, 10801, 11358, 11929, 12514, 13113, 13726

Offset

1,1

Links

Colin Barker, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Clique

Eric Weisstein's World of Mathematics, Fiveleaper Graph

Wikipedia, Clique

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Formula

a(n) = 7*n^2 - 38*n + 49 for n > 4.

From Colin Barker, Jun 10 2019: (Start)

G.f.: x*(2 - x + x^2 + 8*x^4 + 12*x^5 - 8*x^6) / (1 - x)^3.

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>7.

(End)

Prog

(PARI) Vec(x*(2 - x + x^2 + 8*x^4 + 12*x^5 - 8*x^6) / (1 - x)^3 + O(x^40)) \\ Colin Barker, Jun 10 2019

Crossrefs

Sequence in context: A342172 A262406 A308600 * A018315 A146220 A054964

Adjacent sequences: A308601 A308602 A308603 * A308605 A308606 A308607

Keyword

nonn,easy

Author

Eric W. Weisstein, Jun 10 2019

Status

approved