login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Powers of 45.
4

%I #36 Jul 12 2023 12:47:59

%S 1,45,2025,91125,4100625,184528125,8303765625,373669453125,

%T 16815125390625,756680642578125,34050628916015625,1532278301220703125,

%U 68952523554931640625,3102863559971923828125,139628860198736572265625

%N Powers of 45.

%C 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.

%C 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

%H T. D. Noe, <a href="/A009989/b009989.txt">Table of n, a(n) for n = 0..100</a>

%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (45).

%F G.f.: 1/(1-45*x). - _Philippe Deléham_, Nov 24 2008

%F a(n) = 45^n; a(n) = 45*a(n-1), a(0)=1. - _Vincenzo Librandi_, Nov 21 2010

%t 45^Range[0,20] (* _Harvey P. Dale_, May 09 2012 *)

%o (Magma)[45^n: n in [0..20]] // _Vincenzo Librandi_, Nov 21 2010

%o (PARI) a(n)=45^n \\ _Charles R Greathouse IV_, Oct 07 2015

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_