cp's OEIS Frontend

A241696 Number of Carlitz compositions of n with exactly six descents.

%I A241696 #6 Apr 28 2014 09:26:12
%S A241696 13,81,336,1151,3437,9286,23271,54846,122857,263680,545412,1092394,
%T A241696 2126688,4036767,7490050,13614573,24287970,42592752,73525406,
%U A241696 125089010,209962350,348026885,570159824,923885796,1481735623,2353522164,3704254256,5780115565,8945915366
%N A241696 Number of Carlitz compositions of n with exactly six descents.
%C A241696 No two adjacent parts of a Carlitz composition are equal.
%H A241696 Alois P. Heinz, <a href="/A241696/b241696.txt">Table of n, a(n) for n = 18..1000</a>
%p A241696 b:= proc(n, i) option remember; `if`(n=0, 1,
%p A241696        convert(series(add(`if`(i=j, 0, b(n-j, j)*
%p A241696       `if`(j<i, x, 1)), j=1..n), x, 7), polynom))
%p A241696     end:
%p A241696 a:= n-> coeff(b(n, 0), x, 6):
%p A241696 seq(a(n), n=18..50);
%Y A241696 Column k=6 of A241701.
%K A241696 nonn
%O A241696 18,1
%A A241696 _Alois P. Heinz_, Apr 27 2014