OFFSET
0,1
COMMENTS
The squares of these terms appear in A159256. - Elmo R. Oliveira, Sep 15 2024
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2).
FORMULA
G.f.: 21/(1-2*x).
a(n) = 2*a(n-1). - Vincenzo Librandi, Jul 08 2016
From Elmo R. Oliveira, Sep 14 2024: (Start)
E.g.f.: 21*exp(2*x).
a(n) = 21*A000079(n). (End)
MATHEMATICA
Table[21 2^n, {n, 0, 40}] (* Vincenzo Librandi, Jul 08 2016 *)
PROG
(Magma) [21*2^n: n in [0..100]];
(PARI) a(n)=21<<n \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
nonn,easy,changed
AUTHOR
Vincenzo Librandi, Dec 05 2010
STATUS
approved