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A013732
a(n) = 3^(3*n + 1).
4
3, 81, 2187, 59049, 1594323, 43046721, 1162261467, 31381059609, 847288609443, 22876792454961, 617673396283947, 16677181699666569, 450283905890997363, 12157665459056928801, 328256967394537077627, 8862938119652501095929
OFFSET
0,1
FORMULA
From Philippe Deléham, Nov 25 2008: (Start)
a(n) = 27*a(n-1); a(0)=3.
G.f.: 3/(1-27*x). (End)
MAPLE
seq(3^(3*n+1), n=0..15); # Nathaniel Johnston, Jun 26 2011
MATHEMATICA
NestList[27#&, 3, 20] (* Harvey P. Dale, Apr 01 2018 *)
PROG
(Magma) [3^(3*n+1): n in [0..25]]; // Vincenzo Librandi, May 25 2011
(PARI) a(n)=3^(3*n+1) \\ Charles R Greathouse IV, Jul 11 2016
CROSSREFS
KEYWORD
nonn,easy
STATUS
approved