A277031 Number T(n,k) of permutations of [n] where the minimal cyclic distance between elements of the same cycle equals k (k=n for the identity permutation in S_n); triangle T(n,k), n>=0, 0<=k<=n, read by rows.
1, 0, 1, 0, 1, 1, 0, 5, 0, 1, 0, 20, 3, 0, 1, 0, 109, 10, 0, 0, 1, 0, 668, 44, 7, 0, 0, 1, 0, 4801, 210, 28, 0, 0, 0, 1, 0, 38894, 1320, 90, 15, 0, 0, 0, 1, 0, 353811, 8439, 554, 75, 0, 0, 0, 0, 1, 0, 3561512, 63404, 3542, 310, 31, 0, 0, 0, 0, 1, 0, 39374609, 517418, 23298, 1276, 198, 0, 0, 0, 0, 0, 1
Offset: 0
Examples
T(3,1) = 5: (1,2,3), (1,3,2), (1)(2,3), (1,2)(3), (1,3)(2). T(3,3) = 1: (1)(2)(3). Triangle T(n,k) begins: 1; 0, 1; 0, 1, 1; 0, 5, 0, 1; 0, 20, 3, 0, 1; 0, 109, 10, 0, 0, 1; 0, 668, 44, 7, 0, 0, 1; 0, 4801, 210, 28, 0, 0, 0, 1; 0, 38894, 1320, 90, 15, 0, 0, 0, 1; 0, 353811, 8439, 554, 75, 0, 0, 0, 0, 1; 0, 3561512, 63404, 3542, 310, 31, 0, 0, 0, 0, 1; ...
Links
- Alois P. Heinz, Rows n = 0..12, flattened
- Per Alexandersson et al., d-regular partitions and permutations, MathOverflow, 2014