Triangle read by rows: T(n,k) is the number of permutations of [n] having k cycles with at most 2 alternating runs (it is assumed that the smallest element of the cycle is in the first position), 0<=k<=n.
A187247
Triangle read by rows: T(n,k) is the number of permutations of [n] having k cycles with at most 2 alternating runs (it is assumed that the smallest element of the cycle is in the first position), 0<=k<=n.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =0a(7) =2a(8) =3a(9) =1a(10) =2a(11) =4a(12) =11a(13) =6a(14) =1a(15) =16a(16) =18a(17) =40a(18) =35a(19) =10a(20) =1a(21) =104a(22) =142a(23) =178a(24) =195a(25) =85a(26) =15a(27) =1a(28) =688a(29) =1236
External references
- oeis: A187247