A133679 a(n) = 7*a(n-1) + 56*a(n-2) for n>=3, a(0)=1, a(1)=7, a(2)=98.

1, 7, 98, 1078, 13034, 151606, 1791146, 21027958, 247499882, 2910064822, 34230447146, 402576760054, 4734942360554, 55688895086902, 654979037799338, 7703431389461878, 90602845842996074, 1065612078710837686, 12533043918183643946

Offset: 0

Author

Philippe Deléham, Dec 31 2007

Keywords

• easy
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..934
• Index entries for linear recurrences with constant coefficients, signature (7,58)

Crossrefs

Cf. A122950.

Programs

Mathematica

CoefficientList[Series[(1 - 7*x^2)/(1 - 7*x - 56*x^2), {x, 0, 20}], x] (* Wesley Ivan Hurt, Jan 21 2017 *)
LinearRecurrence[{7,56},{1,7,98},20] (* Harvey P. Dale, Dec 27 2019 *)

Formula

G.f.: (1 - 7*x^2)/(1 - 7*x - 56*x^2).

a(n) = Sum_{k=0..n} A122950(n,k)*7^k.

Extensions

a(8) and a(13) corrected by Georg Fischer, May 03 2019