Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k long ascents and long descents. A long ascent (descent) in a Dyck path is a maximal sequence of at least 2 consecutive up (down) steps.
A127155
Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k long ascents and long descents. A long ascent (descent) in a Dyck path is a maximal sequence of at least 2 consecutive up (down) steps.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =0a(4) =1a(5) =1a(6) =0a(7) =4a(8) =1a(9) =0a(10) =10a(11) =2a(12) =1a(13) =1a(14) =0a(15) =20a(16) =12a(17) =9a(18) =1a(19) =0a(20) =35a(21) =42a(22) =47a(23) =6a(24) =1a(25) =1a(26) =0a(27) =56a(28) =112a(29) =180
External references
- oeis: A127155