A113438 Third row of A113435.

1, 4, 16, 62, 237, 901, 3418, 12956, 49096, 186029, 704861, 2670692, 10119152, 38341126, 145273353, 550436561, 2085588866, 7902239404, 29941371656, 113447051497, 429847830217, 1628681887876, 6171031956688, 23381874459566, 88593294803061, 335677616363629

Offset: 0

Author

Floor van Lamoen, Nov 04 2005

Keywords

• nonn
• easy

Links

• Colin Barker, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (7,-15,11,-1).

Crossrefs

Cf. A113435.

Programs

Mathematica

CoefficientList[Series[(1 - x)^3/(x^4 - 11*x^3 + 15*x^2 - 7*x + 1), {x, 0, 30}], x] (* Wesley Ivan Hurt, May 28 2015 *)

PARI

Vec(-(x-1)^3 / (x^4-11*x^3+15*x^2-7*x+1) + O(x^100)) \\ Colin Barker, May 28 2015

Formula

a(n) = 7*a(n-1)-15*a(n-2)+11*a(n-3)-a(n-4), n>4.

a(n) = A113435(3n+2).

G.f.: (1-x)^3 / (x^4-11*x^3+15*x^2-7*x+1).

Extensions

Error in recursion and strange things in formula fixed by Colin Barker, May 28 2015