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A009989
Powers of 45.
4
1, 45, 2025, 91125, 4100625, 184528125, 8303765625, 373669453125, 16815125390625, 756680642578125, 34050628916015625, 1532278301220703125, 68952523554931640625, 3102863559971923828125, 139628860198736572265625
OFFSET
0,2
COMMENTS
Same as Pisot sequences E(1, 45), L(1, 45), P(1, 45), T(1, 45). Essentially same as Pisot sequences E(45, 2025), L(45, 2025), P(45, 2025), T(45, 2025). 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 45-colored compositions of n such that no adjacent parts have the same color. - Milan Janjic, Nov 17 2011
FORMULA
G.f.: 1/(1-45*x). - Philippe Deléham, Nov 24 2008
a(n) = 45^n; a(n) = 45*a(n-1), a(0)=1. - Vincenzo Librandi, Nov 21 2010
MATHEMATICA
45^Range[0, 20] (* Harvey P. Dale, May 09 2012 *)
PROG
(Magma)[45^n: n in [0..20]] // Vincenzo Librandi, Nov 21 2010
(PARI) a(n)=45^n \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
Sequence in context: A218747 A121009 A264061 * A095658 A342405 A279439
KEYWORD
nonn,easy
STATUS
approved