A013714 - OEIS

A013714

a(n) = 9^(2*n + 1).

9, 729, 59049, 4782969, 387420489, 31381059609, 2541865828329, 205891132094649, 16677181699666569, 1350851717672992089, 109418989131512359209, 8862938119652501095929, 717897987691852588770249, 58149737003040059690390169, 4710128697246244834921603689

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OFFSET

0,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..150

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (81).

FORMULA

From Philippe Deléham, Nov 25 2008: (Start)

a(n) = 81*a(n-1); a(0)=9.

G.f.: 9/(1-81*x). (End)

From Elmo R. Oliveira, Aug 26 2024: (Start)

E.g.f.: 9*exp(81*x).

a(n) = 3*A013778(n) = A001019(A005408(n)). (End)

MATHEMATICA

9^(2*Range[0, 20]+1) (* or *) NestList[81#&, 9, 20] (* Harvey P. Dale, May 25 2020 *)

PROG

(Magma) [9^(2*n+1): n in [0..20]]; // Vincenzo Librandi, May 26 2011

(PARI) a(n)=9^(2*n+1) \\ Charles R Greathouse IV, Jul 11 2016

CROSSREFS

Cf. A001019, A005408, A013778.

Sequence in context: A053933 A145262 A154026 * A069034 A053847 A053854

Adjacent sequences: A013711 A013712 A013713 * A013715 A013716 A013717

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved