cp's OEIS Frontend

A241697 Number of Carlitz compositions of n with exactly seven descents.

%I A241697 #6 Apr 28 2014 09:24:26
%S A241697 21,150,688,2561,8253,23930,64030,160539,381379,865676,1889308,
%T A241697 3984311,8151834,16234161,31554397,59999259,111824744,204629354,
%U A241697 368190175,652238928,1138836325,1961870558,3337496363,5611246209,9330350788,15353900381,25019429935
%N A241697 Number of Carlitz compositions of n with exactly seven descents.
%C A241697 No two adjacent parts of a Carlitz composition are equal.
%H A241697 Alois P. Heinz, <a href="/A241697/b241697.txt">Table of n, a(n) for n = 21..1000</a>
%p A241697 b:= proc(n, i) option remember; `if`(n=0, 1,
%p A241697        convert(series(add(`if`(i=j, 0, b(n-j, j)*
%p A241697       `if`(j<i, x, 1)), j=1..n), x, 8), polynom))
%p A241697     end:
%p A241697 a:= n-> coeff(b(n, 0), x, 7):
%p A241697 seq(a(n), n=21..50);
%Y A241697 Column k=7 of A241701.
%K A241697 nonn
%O A241697 21,1
%A A241697 _Alois P. Heinz_, Apr 27 2014