Number of peaks at even levels in all hill-free Dyck paths of semilength n+2 (a hill in a Dyck path is a peak at level 1).
A114590
Number of peaks at even levels in all hill-free Dyck paths of semilength n+2 (a hill in a Dyck path is a peak at level 1).
Terms
- a(0) =1a(1) =2a(2) =8a(3) =28a(4) =103a(5) =382a(6) =1432a(7) =5408a(8) =20546a(9) =78436a(10) =300636a(11) =1156188a(12) =4459267a(13) =17241526a(14) =66807856a(15) =259361920a(16) =1008598126a(17) =3928120924a(18) =15319329472a(19) =59817190552a(20) =233826979750a(21) =914962032172
External references
- oeis: A114590