Triangle read by rows: T(n,k) is the number of permutations of [n] for which the shortest cycle length is k (1<=k<=n).

A145877

Triangle read by rows: T(n,k) is the number of permutations of [n] for which the shortest cycle length is k (1<=k<=n).

Terms

    a(0) =1a(1) =1a(2) =1a(3) =4a(4) =0a(5) =2a(6) =15a(7) =3a(8) =0a(9) =6a(10) =76a(11) =20a(12) =0a(13) =0a(14) =24a(15) =455a(16) =105a(17) =40a(18) =0a(19) =0a(20) =120a(21) =3186a(22) =714a(23) =420a(24) =0a(25) =0a(26) =0a(27) =720a(28) =25487a(29) =5845

External references