A241699 - OEIS

%I #6 Apr 28 2014 09:21:18

%S 55,491,2689,11608,42795,140589,422681,1183166,3121247,7830626,

%T 18812643,43515886,97340687,211323653,446587109,921008294,1857606992,

%U 3670974168,7119426996,13569286673,25448188412,47013582854,85641353036,153964392218,273387455379

%N Number of Carlitz compositions of n with exactly nine descents.

%C No two adjacent parts of a Carlitz composition are equal.

%H Alois P. Heinz, <a href="/A241699/b241699.txt">Table of n, a(n) for n = 27..1000</a>

%p b:= proc(n, i) option remember; `if`(n=0, 1,

%p        convert(series(add(`if`(i=j, 0, b(n-j, j)*

%p       `if`(j<i, x, 1)), j=1..n), x, 10), polynom))

%p     end:

%p a:= n-> coeff(b(n, 0), x, 9):

%p seq(a(n), n=27..55);

%Y Column k=9 of A241701.

%K nonn

%O 27,1

%A _Alois P. Heinz_, Apr 27 2014