Number of hill-free Dyck paths of semilength n+3 and having no peaks at even levels (a hill in a Dyck path is a peak at level 1).
A114589
Number of hill-free Dyck paths of semilength n+3 and having no peaks at even levels (a hill in a Dyck path is a peak at level 1).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =7a(4) =17a(5) =43a(6) =110a(7) =286a(8) =753a(9) =2003a(10) =5376a(11) =14540a(12) =39589a(13) =108427a(14) =298512a(15) =825664a(16) =2293271a(17) =6393539a(18) =17885835a(19) =50191175a(20) =141247519a(21) =398537101a(22) =1127203038a(23) =3195229662a(24) =9076078057a(25) =25830193513a(26) =73643406563a(27) =210312889095
External references
- oeis: A114589