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

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 - 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 *)

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

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).