%I #6 Apr 28 2014 19:03:15

%S 14,932,26865,486170,6385041,66251021,572940736,4284412169,

%T 28422470746,170581304048,939549814317,4806572652156,23042550110214,

%U 104344981470162,448963898693786,1845829609158989,7281093726825326,27670464821261399,101613723592257039

%N Number of ballot sequences of length n having exactly eight descents.

%e a(13) = 14: [1,2,1,3,2,1,3,2,1,4,3,2,1], [1,2,1,3,2,1,4,2,1,5,3,2,1], [1,2,1,3,2,1,4,3,1,5,4,2,1], [1,2,1,3,2,1,4,3,2,1,3,2,1], [1,2,1,3,2,1,4,3,2,1,4,2,1], [1,2,1,3,2,1,4,3,2,1,4,3,1], [1,2,1,3,2,1,4,3,2,1,4,3,2], [1,2,1,3,2,1,4,3,2,1,5,2,1], [1,2,1,3,2,1,4,3,2,1,5,3,1], [1,2,1,3,2,1,4,3,2,1,5,3,2], [1,2,1,3,2,1,4,3,2,1,5,4,1], [1,2,1,3,2,1,4,3,2,1,5,4,2], [1,2,1,3,2,1,4,3,2,1,5,4,3], [1,2,1,3,2,1,4,3,2,5,4,3,1].

%Y Column k=8 of A238121 and of A238122.

%K nonn

%O 13,1

%A _Joerg Arndt_ and _Alois P. Heinz_, Apr 28 2014