Number of Dyck paths of semilength n such that no positive level has fewer than three peaks.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =1a(7) =5a(8) =30a(9) =96a(10) =245a(11) =592a(12) =1543a(13) =4884a(14) =17660a(15) =64495a(16) =226442a(17) =766937a(18) =2558655a(19) =8590293a(20) =29408344a(21) =102893203a(22) =366035420a(23) =1314955687a(24) =4747101946a(25) =17184305311a(26) =62359953380a(27) =226978626707a(28) =829122987011