A165133 a(n) = (2^(n+4)-1)*(2^n+1).

30, 93, 315, 1143, 4335, 16863, 66495, 264063, 1052415, 4201983, 16792575, 67139583, 268496895, 1073864703, 4295213055, 17180360703, 68720459775, 274879873023, 1099515559935, 4398054375423, 17592201773055, 70368775634943, 281475039625215

Offset

0,1

Links

Table of n, a(n) for n=0..22.

Index entries for linear recurrences with constant coefficients, signature (7, -14, 8).

Formula

a(n) = 7*a(n-1) -14*a(n-2) +8*a(n-3). G.f.: 3*(10-39*x+28*x^2)/((1-x) * (2*x-1) * (4*x-1)).

a(n) = A000225(n+4) * A000051(n). - Michel Marcus, Jul 17 2013

Mathematica

Table[(2^(n+4)-1)(2^n+1), {n, 0, 30}] (* or *) LinearRecurrence[{7, -14, 8}, {30, 93, 315}, 30] (* Harvey P. Dale, Dec 11 2011 *)

Prog

(Quick Basic) DO: DIM x AS LONG: n = 0: x = ((2 ^ (n + 2)) - 1) * ((2 ^ (n - 2)) + 1): PRINT x: n = n + 1: LOOP
(PARI) a(n)=(2^(n+4)-1)*(2^n+1) \\ Charles R Greathouse IV, Jul 03 2016

Crossrefs

Sequence in context: A042776 A042778 A031212 * A044217 A044598 A033573

Adjacent sequences: A165130 A165131 A165132 * A165134 A165135 A165136

Keyword

nonn,easy

Author

Boris Hostnik (megpplus(AT)siol.net), Sep 04 2009

Extensions

Fractional values removed by R. J. Mathar, Sep 20 2009

Status

approved