A125183 - cp's OEIS frontend

A125183 Triangle read by rows: T(n,k) is the number of permutations p of {1,2,...,n} such that the set {|p(i)-i|, i=1,2,...,n} has exactly k elements (1<=k<=n).

n	a(n)
1	1
2	2
3	0
4	1
5	5
6	0
7	3
8	11
9	6
10	4
11	1
12	28
13	55
14	32
15	4
16	3
17	69
18	210
19	330
20	108
21	0
22	1
23	102
24	846
25	2177
26	1590
27	324
28	0
29	4
30	279
31	2694
32	11221
33	17578
34	7624
35	888
36	32
37	1
38	328
39	7791
40	54777
41	135993
42	123474
43	37524
44	2896
45	96
46	3
47	961
48	24032
49	227906
50	914364
51	1427342
52	839904
53	182824
54	11464
55	0

[1, 2, 0, 1, 5, 0, 3, 11, 6, 4, 1, 28, 55, 32, 4, 3, 69, 210, 330, 108, 0, 1, 102, 846, 2177, 1590, 324, 0, 4, 279, 2694, 11221, 17578, 7624, 888, 32, 1, 328, 7791, 54777, 135993, 123474, 37524, 2896, 96, 3, 961, 24032, 227906, 914364, 1427342, 839904, 182824, 11464, 0]

cp's OEIS Frontend

A125183 Triangle read by rows: T(n,k) is the number of permutations p of {1,2,...,n} such that the set {|p(i)-i|, i=1,2,...,n} has exactly k elements (1<=k<=n).

Table of values

List of values