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1, 27, 729, 19683, 531441, 14348907, 387420489, 10460353203, 282429536481, 7625597484987, 205891132094649, 5559060566555523, 150094635296999121, 4052555153018976267, 109418989131512359209, 2954312706550833698643
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OFFSET
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0,2
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COMMENTS
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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 27-colored compositions of n such that no adjacent parts have the same color. - Milan Janjic, Nov 17 2011
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LINKS
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T. D. Noe, Table of n, a(n) for n = 0..100
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (27).
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FORMULA
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G.f.: 1/(1-27*x). - Philippe Deléham, Nov 24 2008
a(n) = 27^n; a(n) = 27*a(n-1), n > 0; a(0)=1. - Vincenzo Librandi, Nov 21 2010
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PROG
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(Sage) [lucas_number1(n, 27, 0) for n in range(1, 17)] # Zerinvary Lajos, Apr 29 2009
(MAGMA) [27^n: n in [0..100]] // Vincenzo Librandi, Nov 21 2010
(PARI) a(n)=27^n \\ Charles R Greathouse IV, Sep 24 2015
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CROSSREFS
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Sequence in context: A171301 A098838 A268015 * A307388 A046240 A042406
Adjacent sequences: A009968 A009969 A009970 * A009972 A009973 A009974
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KEYWORD
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nonn,easy
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AUTHOR
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N. J. A. Sloane
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STATUS
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approved
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