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A009972 Powers of 28. 11
1, 28, 784, 21952, 614656, 17210368, 481890304, 13492928512, 377801998336, 10578455953408, 296196766695424, 8293509467471872, 232218265089212416, 6502111422497947648, 182059119829942534144, 5097655355238390956032 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

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 28-colored compositions of n such that no adjacent parts have the same color. - Milan Janjic, Nov 17 2011

LINKS

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 (28).

FORMULA

G.f.: 1/(1-28*x). - Philippe Deléham, Nov 24 2008

a(n) = 28^n; a(n) = 28*a(n-1), n > 0, a(0) = 1. - Vincenzo Librandi, Nov 21 2010

MATHEMATICA

28^Range[0, 13] (* Alonso del Arte, Feb 28 2015 *)

PROG

(Sage) [lucas_number1(n, 28, 0) for n in xrange(1, 17)] # Zerinvary Lajos, Apr 29 2009

(MAGMA) [28^n: n in [0..100]] // Vincenzo Librandi, Nov 21 2010

(PARI) a(n)=28^n \\ Charles R Greathouse IV, Sep 28 2015

CROSSREFS

Sequence in context: A189775 A189157 A267732 * A114037 A041365 A042514

Adjacent sequences:  A009969 A009970 A009971 * A009973 A009974 A009975

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified August 23 00:16 EDT 2017. Contains 290953 sequences.