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A013786
a(n) = 7^(4*n + 1).
2
7, 16807, 40353607, 96889010407, 232630513987207, 558545864083284007, 1341068619663964900807, 3219905755813179726837607, 7730993719707444524137094407, 18562115921017574302453163671207, 44567640326363195900190045974568007
OFFSET
0,1
FORMULA
From Philippe Deléham, Dec 02 2008: (Start)
a(n) = 2401*a(n-1); a(0)=7.
G.f.: 7/(1-2401*x).
a(n) = A013787(n)/49. (End)
MATHEMATICA
NestList[2401#&, 7, 20] (* Harvey P. Dale, Oct 04 2024 *)
PROG
(Magma) [7^(4*n+1): n in [0..15]]; // Vincenzo Librandi, Jun 28 2011
(PARI) a(n)=7^(4*n+1) \\ Charles R Greathouse IV, Jul 11 2016
CROSSREFS
Subsequence of A000420.
Sequence in context: A134645 A327840 A115997 * A351326 A285178 A072050
KEYWORD
nonn,easy
STATUS
approved