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Number of Carlitz compositions of n with exactly eight descents.
2

%I #6 Apr 28 2014 09:22:54

%S 34,273,1374,5523,19085,59043,167822,445485,1117320,2671007,6126303,

%T 13552203,29036088,60461206,122706950,243312768,472343731,899329583,

%U 1681962056,3094108766,5605224314,10010276920,17640174861,30699341690,52802429497,89820432080

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

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

%H Alois P. Heinz, <a href="/A241698/b241698.txt">Table of n, a(n) for n = 24..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, 9), polynom))

%p end:

%p a:= n-> coeff(b(n, 0), x, 8):

%p seq(a(n), n=24..50);

%Y Column k=8 of A241701.

%K nonn

%O 24,1

%A _Alois P. Heinz_, Apr 27 2014