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

A288678

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

Terms

    a(0) =1a(1) =0a(2) =1a(3) =1a(4) =1a(5) =4a(6) =14a(7) =35a(8) =91a(9) =268a(10) =864a(11) =2833a(12) =9279a(13) =30670a(14) =102975a(15) =351148a(16) =1212886a(17) =4232714a(18) =14900843a(19) =52865511a(20) =188871400a(21) =679029570a(22) =2455099043a(23) =8922220725a(24) =32576194260a(25) =119447959183a(26) =439700905503

External references