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

Author

Floor van Lamoen, Nov 04 2005

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A113439.

Programs

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 *)

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

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).