Triangle read by rows: T(n,k) is the number of hill-free Dyck paths of semilength n and having k valleys strictly above the x-axis (0<=k<=n-2; n>=2). A hill in a Dyck path is a peak at level 1.
A119011
Triangle read by rows: T(n,k) is the number of hill-free Dyck paths of semilength n and having k valleys strictly above the x-axis (0<=k<=n-2; n>=2). A hill in a Dyck path is a peak at level 1.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =1a(6) =3a(7) =8a(8) =6a(9) =1a(10) =5a(11) =18a(12) =23a(13) =10a(14) =1a(15) =8a(16) =38a(17) =70a(18) =54a(19) =15a(20) =1a(21) =13a(22) =76a(23) =186a(24) =215a(25) =110a(26) =21a(27) =1a(28) =21a(29) =147
External references
- oeis: A119011