A344901 - cp's OEIS frontend

A344901 Triangle read by rows: T(n,k) is the number of permutations of length n that have k same elements at the same positions with its inverse permutation for 0 <= k <= n.

n	a(n)
0	1
1	0
2	1
3	0
4	0
5	2
6	2
7	0
8	0
9	4
10	6
11	8
12	0
13	0
14	10
15	24
16	30
17	40
18	0
19	0
20	26
21	160
22	144
23	180
24	160
25	0
26	0
27	76
28	1140
29	1120
30	1008
31	840
32	700
33	0
34	0
35	232
36	8988
37	9120
38	8960
39	5376
40	4200
41	2912
42	0
43	0
44	764
45	80864
46	80892
47	82080
48	53760
49	30240
50	19656
51	12768
52	0
53	0
54	2620
55	809856
56	808640
57	808920
58	547200
59	336000
60	157248
61	95760
62	55680
63	0
64	0
65	9496

[1, 0, 1, 0, 0, 2, 2, 0, 0, 4, 6, 8, 0, 0, 10, 24, 30, 40, 0, 0, 26, 160, 144, 180, 160, 0, 0, 76, 1140, 1120, 1008, 840, 700, 0, 0, 232, 8988, 9120, 8960, 5376, 4200, 2912, 0, 0, 764, 80864, 80892, 82080, 53760, 30240, 19656, 12768, 0, 0, 2620, 809856, 808640, 808920, 547200, 336000, 157248, 95760, 55680, 0, 0, 9496]

cp's OEIS Frontend

A344901 Triangle read by rows: T(n,k) is the number of permutations of length n that have k same elements at the same positions with its inverse permutation for 0 <= k <= n.

Table of values

List of values