A013786 a(n) = 7^(4*n + 1).

7, 16807, 40353607, 96889010407, 232630513987207, 558545864083284007, 1341068619663964900807, 3219905755813179726837607, 7730993719707444524137094407, 18562115921017574302453163671207, 44567640326363195900190045974568007

Offset

0,1

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 (2401).

Formula

From Philippe Deléham, Dec 02 2008: (Start)

a(n) = 2401*a(n-1); a(0)=7.

G.f.: 7/(1-2401*x).

a(n) = A013787(n)/49. (End)

Mathematica

NestList[2401#&, 7, 20] (* Harvey P. Dale, Oct 04 2024 *)

Prog

(Magma) [7^(4*n+1): n in [0..15]]; // Vincenzo Librandi, Jun 28 2011
(PARI) a(n)=7^(4*n+1) \\ Charles R Greathouse IV, Jul 11 2016

Crossrefs

Subsequence of A000420.

Sequence in context: A134645 A327840 A115997 * A351326 A285178 A072050

Adjacent sequences: A013783 A013784 A013785 * A013787 A013788 A013789

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved