Number of Dyck paths of semilength n which satisfy the condition: number of returns + number of hills < number of peaks.

A217539

Number of Dyck paths of semilength n which satisfy the condition: number of returns + number of hills < number of peaks.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =4a(5) =17a(6) =66a(7) =252a(8) =946a(9) =3523a(10) =13054a(11) =48248a(12) =178146a(13) =657813a(14) =2430962a(15) =8995521a(16) =33342588a(17) =123822171a(18) =460772982a(19) =1718304786a(20) =6421729878a(21) =24051429321a(22) =90272123682a(23) =339522804129

External references