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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
OFFSET
0,2
COMMENTS
Same as Pisot sequences E(1, 28), L(1, 28), P(1, 28), T(1, 28). Essentially same as Pisot sequences E(28, 784), L(28, 784), P(28, 784), T(28, 784). 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 28-colored compositions of n such that no adjacent parts have the same color. - Milan Janjic, Nov 17 2011
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 *)
NestList[28#&, 1, 20] (* Harvey P. Dale, Jan 19 2019 *)
PROG
(Sage) [lucas_number1(n, 28, 0) for n in range(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
KEYWORD
nonn,easy
STATUS
approved