A241801 Number of ballot sequences of length n having exactly eight descents.

14, 932, 26865, 486170, 6385041, 66251021, 572940736, 4284412169, 28422470746, 170581304048, 939549814317, 4806572652156, 23042550110214, 104344981470162, 448963898693786, 1845829609158989, 7281093726825326, 27670464821261399, 101613723592257039

Offset

13,1

Links

Table of n, a(n) for n=13..31.

Example

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].

Crossrefs

Column k=8 of A238121 and of A238122.

Sequence in context: A340259 A269610 A115458 * A337576 A350566 A199651

Adjacent sequences: A241798 A241799 A241800 * A241802 A241803 A241804

Keyword

nonn

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Status

approved