A239081 Number of self-inverse permutations p on [n] with displacement of elements restricted by 9: |p(i)-i| <= 9.

1, 1, 2, 4, 10, 26, 76, 232, 764, 2620, 9496, 33076, 112428, 372436, 1214976, 3913582, 12529522, 39989374, 127728664, 409169795, 1317486613, 4256424244, 13780938480, 44667060684, 144831314468, 469535390016, 1521506451968, 4927356770176, 15947637013296

Offset: 0

Author

Joerg Arndt and Alois P. Heinz, Mar 10 2014

Keywords

• nonn

Links

• Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 0..1000

Crossrefs

Column k=9 of A238888.

Cf. A000085.