A113442 Third row of A113439.

1, 4, 17, 72, 306, 1305, 5577, 23858, 102108, 437080, 1871065, 8009866, 34289712, 146792138, 628407994, 2690174883, 11516466985, 49301256865, 211055514017, 903515089697, 3867890010850, 16558188448465, 70884540117396

Offset

0,2

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).

Formula

a(n) = A113439(4*n+2).

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

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

Mathematica

CoefficientList[Series[-(1 - 5*x + 9*x^2 - 7*x^3 + 2*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(-(1-5*x+9*x^2-7*x^3+2*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: A001076 A122451 A257388 * A362908 A085732 A289159

Adjacent sequences: A113439 A113440 A113441 * A113443 A113444 A113445

Keyword

nonn,easy

Author

Floor van Lamoen, Nov 04 2005

Status

approved