A013780 a(n) = 4^(4*n + 1).

4, 1024, 262144, 67108864, 17179869184, 4398046511104, 1125899906842624, 288230376151711744, 73786976294838206464, 18889465931478580854784, 4835703278458516698824704, 1237940039285380274899124224

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200
• Tanya Khovanova, Recursive Sequences
• Index entries for linear recurrences with constant coefficients, signature (256).

Programs

Magma

[4^(4*n+1): n in [0..15]]; // Vincenzo Librandi, Jun 17 2011

Mathematica

NestList[256#&,4,20] (* Harvey P. Dale, Aug 09 2013 *)

PARI

a(n)=4^(4*n+1) \\ Charles R Greathouse IV, Jul 11 2016

Formula

From Philippe Deléham, Nov 27 2008: (Start)

a(n) = 256*a(n-1); a(0)=4.

G.f.: 4/(1-256*x). (End)