A001883 - cp's OEIS frontend

A001883 Number of permutations s of {1,2,...,n} such that |s(i)-i|>1 for each i=1,2,...,n.

n	a(n)
0	1
1	0
2	0
3	0
4	1
5	4
6	29
7	206
8	1708
9	15702
10	159737
11	1780696
12	21599745
13	283294740
14	3995630216
15	60312696452
16	970234088153
17	16571597074140
18	299518677455165
19	5711583170669554
20	114601867572247060
21	2413623459384988298
22	53238503492701261201
23	1227382998752177970288
24	29520591675204638641249

[1, 0, 0, 0, 1, 4, 29, 206, 1708, 15702, 159737, 1780696, 21599745, 283294740, 3995630216, 60312696452, 970234088153, 16571597074140, 299518677455165, 5711583170669554, 114601867572247060, 2413623459384988298, 53238503492701261201, 1227382998752177970288, 29520591675204638641249]

cp's OEIS Frontend

A001883 Number of permutations s of {1,2,...,n} such that |s(i)-i|>1 for each i=1,2,...,n.

Table of values

List of values