A013710 a(n) = 5^(2*n + 1).

5, 125, 3125, 78125, 1953125, 48828125, 1220703125, 30517578125, 762939453125, 19073486328125, 476837158203125, 11920928955078125, 298023223876953125, 7450580596923828125, 186264514923095703125, 4656612873077392578125, 116415321826934814453125, 2910383045673370361328125

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 (25).

Crossrefs

Cf. A000351, A005408, A009969.

Programs

Magma

[5^(2*n+1): n in [0..20]]; // Vincenzo Librandi, May 26 2011

Mathematica

NestList[25#&,5,20] (* Harvey P. Dale, Aug 08 2013 *)

PARI

a(n)=5^(2*n+1) \\ Charles R Greathouse IV, Jul 11 2016

Formula

From Philippe Deléham, Nov 23 2008: (Start)

a(n) = 25*a(n-1); a(0)=5.

G.f.: 5/(1-25*x). (End)

E.g.f.: 5*exp(25*x). - Mohammad K. Azarian, Dec 23 2008

a(n) = 5*A009969(n) = A000351(A005408(n)). - Elmo R. Oliveira, Aug 26 2024