A181961 Number of independent sets of nodes in graph C_6 x P_n (n>=0).

1, 18, 199, 2309, 26660, 307983, 3557711, 41097664, 474748249, 5484153915, 63351353194, 731816432741, 8453730886601, 97655043951558, 1128082705387895, 13031283779122753, 150533605489179940, 1738920490541077131, 20087504465180492695, 232045017488460324836

Offset: 0

Author

Cesar Bautista, Apr 04 2012

Keywords

• nonn
• easy

Links

• Cesar Bautista, Table of n, a(n) for n = 0..219
• C. Bautista-Ramos and C. Guillen-Galvan, Fibonacci numbers of generalized Zykov sums, J. Integer Seq., 15 (2012), Article 12.7.8.
• Index entries for linear recurrences with constant coefficients, signature (12,-3,-25,-2,1).

Crossrefs

Row 6 of A286513.

Programs

PARI

Vec((1+6*x-14*x^2+x^4)/(1-12*x+3*x^2+25*x^3+2*x^4-x^5)+O(x^99)) \\ Charles R Greathouse IV, Apr 04 2012

Formula

a(n) = 12*a(n-1)-3*a(n-2)-25*a(n-3)-2*a(n-4)+a(n-5) for n>=5, with a(0)=1, a(1)=18, a(2)=199, a(3)=2309, a(4)=26660.

G.f.: (1 + 6*x - 14*x^2 + x^4)/(1 - 12*x + 3*x^2 + 25*x^3 + 2*x^4 - x^5). - Charles R Greathouse IV, Apr 04 2012