A288541 Number of Dyck paths of semilength n such that the minimal number of peaks over all positive levels equals two.

1, 0, 0, 3, 13, 30, 61, 172, 619, 2241, 7736, 25786, 85315, 286653, 986444, 3465777, 12342188, 44275218, 159463056, 576136367, 2089063623, 7607265038, 27829092314, 102263653872, 377340952123, 1397457667346, 5192248524833, 19348310336881, 72292940817636

Offset: 2

Author

Alois P. Heinz, Jun 11 2017

Keywords

• nonn

Examples

			: a(5) = 3:
:
:            /\/\      /\/\      /\/\
:       /\/\/    \  /\/    \/\  /    \/\/\  .
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 2..300
• Wikipedia, Counting lattice paths

Crossrefs

Column k=2 of A288387.

Cf. A000108.