A152110 G.f.: -2*(-2 - 11*x - 4*x^2 + x^3)/(x - 1)^4.

4, 38, 136, 330, 652, 1134, 1808, 2706, 3860, 5302, 7064, 9178, 11676, 14590, 17952, 21794, 26148, 31046, 36520, 42602, 49324, 56718, 64816, 73650, 83252, 93654, 104888, 116986, 129980, 143902, 158784, 174658, 191556, 209510, 228552, 248714

Offset: 0

Author

N. J. A. Sloane, Sep 21 2009, based on email from R. J. Mathar, Mar 22 2009

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A006071.

Programs

Magma

I:=[4,38,136,330]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 11 2012

Mathematica

CoefficientList[Series[-2*(-2 - 11*x - 4*x^2 + x^3)/(x - 1)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Dec 11 2012 *)

Formula

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). a(n) = 2*(n+1)*(8*n^2 + 8*n + 3)/3 = A152133(2*n-1). - R. J. Mathar, Sep 22 2009

Extensions

More terms from R. J. Mathar, Sep 22 2009