Number of Dyck n-paths all of whose ascents have lengths equal to 1 (mod 6).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =2a(8) =9a(9) =37a(10) =121a(11) =331a(12) =793a(13) =1718a(14) =3454a(15) =6646a(16) =12841a(17) =26589a(18) =61813a(19) =158918a(20) =426401a(21) =1134431a(22) =2914055a(23) =7171539a(24) =16967745a(25) =39008002a(26) =88529366a(27) =202057561a(28) =471422866a(29) =1133448790