A289632 - cp's OEIS frontend

A289632 Triangle read by rows: T(n-1,k), where n >= 2 and 1 <= k <= floor(n/2), is the number of permutations of (1, 2, ..., n) having k consecutive pairs but no consecutive sequences of length greater than 2.

n	a(n)
2	1
3	2
4	9
5	1
6	44
7	9
8	265
9	66
10	3
11	1854
12	530
13	44
14	14833
15	4635
16	530
17	11
18	133496
19	44499
20	6180
21	265
22	1334961
23	467236
24	74165
25	4635
26	53
27	14684570
28	5339844
29	934472
30	74165
31	1854
32	176214841
33	66080565
34	12459636
35	1168090
36	44499
37	309
38	2290792932
39	881074205
40	176214840

[1, 2, 9, 1, 44, 9, 265, 66, 3, 1854, 530, 44, 14833, 4635, 530, 11, 133496, 44499, 6180, 265, 1334961, 467236, 74165, 4635, 53, 14684570, 5339844, 934472, 74165, 1854, 176214841, 66080565, 12459636, 1168090, 44499, 309, 2290792932, 881074205, 176214840]

cp's OEIS Frontend

A289632 Triangle read by rows: T(n-1,k), where n >= 2 and 1 <= k <= floor(n/2), is the number of permutations of (1, 2, ..., n) having k consecutive pairs but no consecutive sequences of length greater than 2.

Table of values

List of values