Number of Dyck paths of semilength n such that each positive level has exactly six peaks.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =0a(8) =0a(9) =0a(10) =0a(11) =0a(12) =0a(13) =7a(14) =140a(15) =840a(16) =2100a(17) =2310a(18) =924a(19) =0a(20) =49a(21) =2156a(22) =42140a(23) =479220a(24) =3598560a(25) =19184676a(26) =75954564a(27) =229873063a(28) =541427264a(29) =1002386336