Triangle read by rows: T(n,k) (for 0 <= k <= floor(n/2)) is the number of permutations of length n that have k descents and avoid the patterns 321 and 2341.
A304429
Triangle read by rows: T(n,k) (for 0 <= k <= floor(n/2)) is the number of permutations of length n that have k descents and avoid the patterns 321 and 2341.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =4a(6) =1a(7) =10a(8) =2a(9) =1a(10) =20a(11) =13a(12) =1a(13) =35a(14) =49a(15) =4a(16) =1a(17) =56a(18) =140a(19) =36a(20) =1a(21) =84a(22) =336a(23) =181a(24) =8a(25) =1a(26) =120a(27) =714a(28) =670a(29) =92
External references
- oeis: A304429