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

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =1a(9) =1a(10) =8a(11) =29a(12) =71a(13) =148a(14) =302a(15) =596a(16) =1101a(17) =1915a(18) =3485a(19) =8991a(20) =32879a(21) =131942a(22) =595068a(23) =2731434a(24) =11077722a(25) =38438377a(26) =117144042a(27) =324706536a(28) =842734665a(29) =2087025088