Triangle read by rows: T(n,k) gives the number of ballot sequences of length n having exactly k flat steps, n>=0, 0<=k<=n.
A238125
Triangle read by rows: T(n,k) gives the number of ballot sequences of length n having exactly k flat steps, n>=0, 0<=k<=n.
Terms
- a(0) =1a(1) =1a(2) =0a(3) =1a(4) =1a(5) =0a(6) =2a(7) =1a(8) =1a(9) =0a(10) =4a(11) =3a(12) =2a(13) =1a(14) =0a(15) =9a(16) =8a(17) =6a(18) =2a(19) =1a(20) =0a(21) =22a(22) =24a(23) =17a(24) =9a(25) =3a(26) =1a(27) =0a(28) =59a(29) =70
External references
- oeis: A238125