A332348 Number of maximal independent sets in the 3 X n king graph.

1, 2, 6, 8, 22, 40, 82, 176, 340, 722, 1450, 2966, 6096, 12362, 25384, 51728, 105698, 216074, 440962, 901396, 1840686, 3760232, 7681828, 15689962, 32053346, 65473214, 133745304, 273208346, 558081744, 1140024080, 2328745042, 4757002434, 9717279194, 19849727740

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (1,2,1,-2,2,-2).

Formula

a(n) = a(n-1) + 2*a(n-2) + a(n-3) - 2*a(n-4) + 2*a(n-5) - 2*a(n-6) for n >= 6.

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

Prog

(PARI) Vec((1 + x + 2*x^2 - 3*x^3 + 2*x^4 - 2*x^5)/(1 - x - 2*x^2 - x^3 + 2*x^4 - 2*x^5 + 2*x^6) + O(x^40))

Crossrefs

Row n=3 of A332347.

Sequence in context: A129342 A045654 A081672 * A137072 A153802 A217019

Adjacent sequences: A332345 A332346 A332347 * A332349 A332350 A332351

Keyword

nonn,easy

Author

Andrew Howroyd, Feb 10 2020

Status

approved