A241794 Number of ballot sequences of length n having exactly one descent.

1, 5, 16, 43, 99, 215, 430, 834, 1529, 2765, 4792, 8216, 13684, 22575, 36402, 58285, 91617, 143097, 220317, 337100, 509718, 766655, 1141457, 1690994, 2484138, 3631902, 5271297, 7617750, 10937657, 15640771, 22240250, 31502316, 44396662, 62345539, 87149572

Offset: 3

Author

Joerg Arndt and Alois P. Heinz, Apr 28 2014

Keywords

• nonn

Examples

			a(3) = 1: [1,2,1].
a(4) = 5: [1,1,2,1], [1,2,1,1], [1,2,1,2], [1,2,1,3], [1,2,3,1].
		

Crossrefs

Column k=1 of A238121 and of A238122.