A241695 - OEIS

%I #6 Apr 28 2014 09:27:55

%S 8,43,159,497,1365,3412,7959,17529,36820,74341,145037,274632,506546,

%T 912668,1610174,2787338,4742439,7942378,13109810,21351242,34344574,

%U 54611144,85907033,133783286,206382165,315561476,478474684,719778651,1074701635,1593288000

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

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

%H Alois P. Heinz, <a href="/A241695/b241695.txt">Table of n, a(n) for n = 15..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, 6), polynom))

%p     end:

%p a:= n-> coeff(b(n, 0), x, 5):

%p seq(a(n), n=15..50);

%Y Column k=5 of A241701.

%K nonn

%O 15,1

%A _Alois P. Heinz_, Apr 27 2014