A113441 Second row of A113439.

1, 3, 12, 50, 212, 905, 3872, 16576, 70968, 303832, 1300737, 5568473, 23838453, 102051167, 436874885, 1870233780, 8006350999, 34274673894, 146727674181, 628131735844, 2688991567300, 11511399994065, 49279563214531

Offset

0,2

Links

Table of n, a(n) for n=0..22.

Index entries for linear recurrences with constant coefficients, signature (9, -28, 38, -20, 1).

Formula

a(n) = A113439(4*n+1).

a(n) = 9*a(n-1) - 28*a(n-2) + 38*a(n-3) - 20*a(n-4) + a(n-5).

G.f.: -(1-6*x+13*x^2-12*x^3+4*x^4)/(-1+9*x-28*x^2+38*x^3-20*x^4+x^5).

Mathematica

LinearRecurrence[{9, -28, 38, -20, 1}, {1, 3, 12, 50, 212}, 30] (* Harvey P. Dale, Apr 06 2013 *)
CoefficientList[Series[-(1 - 6*x + 13*x^2 - 12*x^3 + 4*x^4)/(-1 + 9*x - 28*x^2 + 38*x^3 - 20*x^4 + x^5), {x, 0, 50}], x] (* G. C. Greubel, Mar 11 2017 *)

Prog

(PARI) x='x+O('x^50); Vec(-(1-6*x+13*x^2-12*x^3+4*x^4)/(-1+9*x-28*x^2+38*x^3-20*x^4+x^5)) \\ G. C. Greubel, Mar 11 2017

Crossrefs

Cf. A113439.

Sequence in context: A092443 A356280 A108080 * A119976 A074547 A151178

Adjacent sequences: A113438 A113439 A113440 * A113442 A113443 A113444

Keyword

nonn,easy

Author

Floor van Lamoen, Nov 04 2005

Status

approved