A113440 First row of A113439.

1, 2, 8, 34, 146, 627, 2689, 11521, 49337, 211233, 904306, 3871305, 16572812, 70947073, 303719624, 1300203634, 5566087073, 23828058969, 102006385362, 436682772844, 1869410868456, 8002827727921, 34259590954322

Offset: 0

Author

Floor van Lamoen, Nov 04 2005

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (9,-28,38,-20,1).

Crossrefs

Cf. A113439.

Programs

Mathematica

CoefficientList[Series[-(1 - 7*x + 18*x^2 - 20*x^3 + 8*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 *)
LinearRecurrence[{9,-28,38,-20,1},{1,2,8,34,146},30] (* Harvey P. Dale, Jul 20 2024 *)

PARI

x='x+O('x^50); Vec(-(1-7*x+18*x^2-20*x^3+8*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).

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

G.f.: -(1-7*x+18*x^2-20*x^3+8*x^4)/(-1+9*x-28*x^2+38*x^3-20*x^4+x^5).