A013894 a(n) = 20^(5*n + 1).

20, 64000000, 204800000000000, 655360000000000000000, 2097152000000000000000000000, 6710886400000000000000000000000000, 21474836480000000000000000000000000000000, 68719476736000000000000000000000000000000000000, 219902325555200000000000000000000000000000000000000000

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..50

Tanya Khovanova, Recursive Sequences.

Index entries for linear recurrences with constant coefficients, signature (3200000).

Formula

a(n) = 3200000*a(n-1), a(0)=20. - Vincenzo Librandi, May 27 2011

From Elmo R. Oliveira, Jul 11 2025: (Start)

G.f.: 20/(1-3200000*x).

E.g.f.: 20*exp(3200000*x).

a(n) = A013822(n)*A013854(n) = A009964(A016861(n)). (End)

Mathematica

NestList[3200000*# &, 20, 10] (* Paolo Xausa, Jul 13 2025 *)

Prog

(Magma) [20^(5*n+1): n in [0..10]]; // Vincenzo Librandi, May 27 2011

Crossrefs

Subsequence of A009964.

Cf. A013822, A013854, A016861.

Sequence in context: A180725 A013812 A386795 * A128671 A172766 A048948

Adjacent sequences: A013891 A013892 A013893 * A013895 A013896 A013897

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved