A216118 - cp's OEIS frontend

A216118 Triangle read by rows: T(n,k) is the number of stretching pairs in all permutations in S_{n,k} (=set of permutations in S_n with k cycles) (n >= 3; 1 <= k <= n-2).

n	a(n)
3	0
4	1
5	1
6	10
7	15
8	5
9	90
10	165
11	90
12	15
13	840
14	1750
15	1225
16	350
17	35
18	8400
19	19180
20	15750
21	5950
22	1050
23	70
24	90720
25	222264
26	204624
27	92610
28	22050
29	2646
30	126
31	1058400
32	2744280
33	2757720
34	1421490
35	411600
36	67620
37	5880
38	210
39	13305600
40	36162720
41	38980920
42	22203720
43	7408170
44	1496880
45	180180
46	11880
47	330

[0, 1, 1, 10, 15, 5, 90, 165, 90, 15, 840, 1750, 1225, 350, 35, 8400, 19180, 15750, 5950, 1050, 70, 90720, 222264, 204624, 92610, 22050, 2646, 126, 1058400, 2744280, 2757720, 1421490, 411600, 67620, 5880, 210, 13305600, 36162720, 38980920, 22203720, 7408170, 1496880, 180180, 11880, 330]

cp's OEIS Frontend

A216118 Triangle read by rows: T(n,k) is the number of stretching pairs in all permutations in S_{n,k} (=set of permutations in S_n with k cycles) (n >= 3; 1 <= k <= n-2).

Table of values

List of values