A128798 n*(n-1)*4^n.

0, 0, 32, 384, 3072, 20480, 122880, 688128, 3670016, 18874368, 94371840, 461373440, 2214592512, 10468982784, 48855252992, 225485783040, 1030792151040, 4672924418048, 21028159881216, 94008244174848, 417814418554880

Offset: 0

Author

Mohammad K. Azarian, Apr 07 2007

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (12,-48,64).

Crossrefs

Cf. A036289, A007758.

Programs

Magma

[(n^2-n)*4^n: n in [0..20]]; // Vincenzo Librandi, Feb 10 2013

Mathematica

CoefficientList[Series[32 x^2/(1 - 4 x)^3, {x, 0, 30}], x] (* Vincenzo Librandi, Feb 10 2013 *)
LinearRecurrence[{12,-48,64},{0,0,32},30] (* Harvey P. Dale, Dec 23 2015 *)

Formula

G.f.: 32*x^2/(1 - 4*x)^3. - Vincenzo Librandi, Feb 10 2013

a(n) =32*A038845(n-2). - R. J. Mathar, Apr 26 2015