A128798 a(n) = 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

0,3

Links

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

Index entries for linear recurrences with constant coefficients, signature (12,-48,64).

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

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 *)

Prog

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

Crossrefs

Cf. A036289, A007758.

Sequence in context: A300879 A301489 A087024 * A086942 A247995 A247996

Adjacent sequences: A128795 A128796 A128797 * A128799 A128800 A128801

Keyword

nonn,easy

Author

Mohammad K. Azarian, Apr 07 2007

Status

approved