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A009983
Powers of 39.
6
1, 39, 1521, 59319, 2313441, 90224199, 3518743761, 137231006679, 5352009260481, 208728361158759, 8140406085191601, 317475837322472439, 12381557655576425121, 482880748567480579719, 18832349194131742609041
OFFSET
0,2
COMMENTS
Same as Pisot sequences E(1, 39), L(1, 39), P(1, 39), T(1, 39). Essentially same as Pisot sequences E(39, 1521), L(39, 1521), P(39, 1521), T(39, 1521). See A008776 for definitions of Pisot sequences.
The compositions of n in which each natural number is colored by one of p different colors are called p-colored compositions of n. For n >= 1, a(n) equals the number of 39-colored compositions of n such that no adjacent parts have the same color. - Milan Janjic, Nov 17 2011
FORMULA
G.f.: 1/(1-39*x). - Philippe Deléham, Nov 24 2008
a(n) = 39^n; a(n) = 39*a(n-1), a(0)=1. - Vincenzo Librandi, Nov 21 2010
MATHEMATICA
39^Range[0, 20] (* Harvey P. Dale, Dec 02 2010 *)
PROG
(Magma)[39^n: n in [0..20]] // Vincenzo Librandi, Nov 21 2010
(PARI) a(n)=39^n \\ Charles R Greathouse IV, Nov 18 2011
CROSSREFS
Sequence in context: A170758 A218741 A112617 * A269028 A158768 A139191
KEYWORD
nonn,easy
STATUS
approved