Number of Dyck paths of semilength n such that each level has exactly seven peaks or no peaks.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =1a(8) =1a(9) =7a(10) =22a(11) =48a(12) =93a(13) =180a(14) =331a(15) =575a(16) =1150a(17) =3578a(18) =13268a(19) =50808a(20) =217173a(21) =881980a(22) =3064454a(23) =9169075a(24) =24605669a(25) =61450068a(26) =147038896a(27) =347902716a(28) =860591396a(29) =2411664484