OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (3).
FORMULA
From Vincenzo Librandi, Sep 15 2011: (Start)
G.f.: 7/(1-3*x).
a(n) = 3*a(n-1), a(0)=7. (End)
E.g.f.: 7*exp(3*x). - Stefano Spezia, Aug 28 2023
MATHEMATICA
7*3^Range[0, 60] (* Vladimir Joseph Stephan Orlovsky, Jun 09 2011 *)
NestList[3#&, 7, 30] (* Harvey P. Dale, May 05 2016 *)
PROG
(Magma) [7*3^n: n in [0..30]]; // Vincenzo Librandi, Sep 15 2011
(PARI) a(n)=7*3^n \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved