A091927 Expansion of (1-6x)/(1-6x-5x^2).

1, 0, 5, 30, 205, 1380, 9305, 62730, 422905, 2851080, 19221005, 129581430, 873593605, 5889468780, 39704780705, 267676028130, 1804580072305, 12165860574480, 82018063808405, 552937685722830, 3727716433379005

Offset: 0

Author

Paul Barry, Feb 13 2004

Keywords

• easy
• nonn

Comments

Let the generating matrix of the Golay G_12 code be [I|B]. Then a(n)=(B^n)_1,1.

Links

• Index entries for linear recurrences with constant coefficients, signature (6,5).

Crossrefs

Cf. A015551.

Programs

Mathematica

CoefficientList[Series[(1-6x)/(1-6x-5x^2),{x,0,30}],x] (* or *) LinearRecurrence[ {6,5},{1,0},30](* Harvey P. Dale, Aug 11 2019 *)

Formula

a(n)=5(sqrt(14)(3+sqrt(14))^(n-1)/28-sqrt(14)(3-sqrt(14))^(n-1)/28)