A165222 a(n) = (2^(n+4)+1)*(2^n+1).

34, 99, 325, 1161, 4369, 16929, 66625, 264321, 1052929, 4203009, 16794625, 67143681, 268505089, 1073881089, 4295245825, 17180426241, 68720590849, 274880135169, 1099516084225, 4398055424001, 17592203870209, 70368779829249

Offset

0,1

Links

Table of n, a(n) for n=0..21.

Formula

a(n) = 7*a(n-1) -14*a(n-2)+8*a(n-3). G.f.: (34-139*x+108*x^2)/((1-x)*(2*x-1)*(4*x-1)). - R. J. Mathar, Sep 20 2009

a(n) = A000051(n) * A000051(n+4). - Michel Marcus, Jul 17 2013

Mathematica

Table[(2^(n+4)+1)(2^n+1), {n, 0, 30}] (* Harvey P. Dale, Mar 18 2022 *)

Prog

(PARI) a(n) = (2^(n+4)+1)*(2^n+1) \\ Michel Marcus, Jul 17 2013

Crossrefs

Sequence in context: A044602 A159904 A282854 * A173308 A044285 A044666

Adjacent sequences: A165219 A165220 A165221 * A165223 A165224 A165225

Keyword

nonn,easy

Author

Boris Hostnik (megpplus(AT)siol.net), Sep 08 2009

Extensions

Two initial fractional values removed by R. J. Mathar, Sep 20 2009

Status

approved