Triangle read by rows: T(n, k) is the number of chains of length k in the poset of permutations of an n-set.
A375835
Triangle read by rows: T(n, k) is the number of chains of length k in the poset of permutations of an n-set.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =2a(5) =1a(6) =0a(7) =6a(8) =8a(9) =3a(10) =0a(11) =24a(12) =64a(13) =59a(14) =18a(15) =0a(16) =120a(17) =574a(18) =970a(19) =695a(20) =180a(21) =0a(22) =720a(23) =5858a(24) =16124a(25) =20240a(26) =11955a(27) =2700a(28) =0a(29) =5040
External references
- oeis: A375835