A128790 n^3*4^n.

0, 4, 128, 1728, 16384, 128000, 884736, 5619712, 33554432, 191102976, 1048576000, 5582618624, 28991029248, 147438174208, 736586891264, 3623878656000, 17592186044416, 84404697300992, 400771988324352, 1885387563728896

Offset

0,2

Comments

All terms are congruent to {0, 2, 4} mod 6 (or mod 9 or mod 18). [Bruno Berselli, Feb 07 2013]

Links

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

Index entries for linear recurrences with constant coefficients, signature (16,-96,256,-256)

Formula

G.f.: 4*x*(1 + 16*x + 16*x^2)/(1 - 4*x)^4. - Vincenzo Librandi, Feb 07 2013

Mathematica

CoefficientList[Series[4*x*(1 + 16*x + 16*x^2)/(1 - 4*x)^4, {x, 0, 30}], x] (* Vincenzo Librandi, Feb 07 2013 *)
Table[n^3 4^n, {n, 0, 20}] (* or *) LinearRecurrence[{16, -96, 256, -256}, {0, 4, 128, 1728}, 20] (* Harvey P. Dale, Nov 24 2022 *)

Prog

(Magma) [n^3*4^n: n in [0..30]]; // Vincenzo Librandi, Feb 07 2013

Crossrefs

Cf. A036289; A007758.

Sequence in context: A152421 A270959 A291851 * A267796 A013823 A321233

Adjacent sequences: A128787 A128788 A128789 * A128791 A128792 A128793

Keyword

nonn,easy

Author

Mohammad K. Azarian, Apr 07 2007

Status

approved