A288539 Number of Dyck paths of semilength n such that at least one positive level has no peaks.

1, 0, 1, 2, 8, 25, 83, 282, 971, 3386, 11940, 42504, 152546, 551426, 2005930, 7337901, 26976726, 99618976, 369349607, 1374391706, 5131186060, 19214759396, 72152791729, 271629133830, 1024989876797, 3876208984221, 14688301498888, 55763768987236, 212077310097784

Offset: 0

Author

Alois P. Heinz, Jun 11 2017

Keywords

• nonn

Comments

a(0) = 1 by convention.

Examples

			: a(3) = 2:
:                 /\
:        /\/\    /  \
:       /    \  /    \  .
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..300
• Wikipedia, Counting lattice paths

Crossrefs

Column k=0 of A288387.

Cf. A000108.