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A173000 a(n) = binomial(n + 4, 4)*9^n. 8

%I

%S 1,45,1215,25515,459270,7440174,111602610,1578379770,21308126895,

%T 277005649635,3490271185401,42835146366285,514021756395420,

%U 6049640671423020,70002984912180660,798034027998859524

%N a(n) = binomial(n + 4, 4)*9^n.

%C Number of n-permutations (n>=4) of 10 objects p, r, q, u, v, w, z, x, y, z with repetition allowed, containing exactly 4 u's.

%H Vincenzo Librandi, <a href="/A173000/b173000.txt">Table of n, a(n) for n = 0..400</a>

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (45,-810,7290,-32805,59049).

%F G.f.: -1 / (9*x-1)^5. - _R. J. Mathar_, Dec 21 2011

%p A173000:=n->binomial(n+4,4)*9^n: seq(A173000(n), n=0..25); # _Wesley Ivan Hurt_, Jul 24 2017

%t Table[Binomial[n + 4, 4]*9^n, {n, 0, 20}]

%o (MAGMA) [Binomial(n+4, 4)*9^n: n in [0..20]]; // _Vincenzo Librandi_, Oct 13 2011

%o (PARI) a(n)=binomial(n+4,4)*9^n \\ _Charles R Greathouse IV_, Oct 07 2015

%K nonn,easy

%O 0,2

%A _Zerinvary Lajos_, Feb 07 2010

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Last modified August 13 05:41 EDT 2020. Contains 336442 sequences. (Running on oeis4.)