A239082 Number of self-inverse permutations p on [n] with displacement of elements restricted by 10: |p(i)-i| <= 10.
1, 1, 2, 4, 10, 26, 76, 232, 764, 2620, 9496, 35696, 130656, 464036, 1615276, 5517828, 18628384, 62330046, 207657610, 690610926, 2299356168, 7678084407, 25759043565, 86697055428, 292427968880, 987581324508, 3337168641756, 11277361448224, 38099089805120
Offset: 0
Keywords
Links
- Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 0..1000