Number of Dyck paths of semilength n such that each positive level up to the highest nonempty level has one or two peaks.

A287963

Number of Dyck paths of semilength n such that each positive level up to the highest nonempty level has one or two peaks.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =10a(6) =28a(7) =71a(8) =194a(9) =532a(10) =1495a(11) =4256a(12) =12176a(13) =35251a(14) =102664a(15) =300260a(16) =881909a(17) =2599948a(18) =7688164a(19) =22788527a(20) =67676144a(21) =201308938a(22) =599676445a(23) =1788564038a(24) =5339905904a(25) =15956230705a(26) =47713265536a(27) =142763240666a(28) =427390085963

External references