Sum of the lengths of the first descents in all hill-free Dyck paths of semilength n (a hill in a Dyck path is a peak at level 1).
A118974
Sum of the lengths of the first descents in all hill-free Dyck paths of semilength n (a hill in a Dyck path is a peak at level 1).
Terms
- a(0) =0a(1) =0a(2) =2a(3) =4a(4) =11a(5) =31a(6) =94a(7) =298a(8) =977a(9) =3283a(10) =11243a(11) =39087a(12) =137569a(13) =489171a(14) =1754596a(15) =6340756a(16) =23063731a(17) =84372061a(18) =310216081a(19) =1145748061a(20) =4248861631a(21) =15814069951a(22) =59054807821a(23) =221197379221a(24) =830819449003
External references
- oeis: A118974