A145891 - cp's OEIS frontend

A145891 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k adjacent pairs of the form (odd,even) (0<=k<=floor(n/2)).

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	4
6	4
7	16
8	4
9	12
10	72
11	36
12	36
13	324
14	324
15	36
16	144
17	1728
18	2592
19	576
20	576
21	9216
22	20736
23	9216
24	576
25	2880
26	57600
27	172800
28	115200
29	14400
30	14400
31	360000
32	1440000
33	1440000
34	360000
35	14400
36	86400
37	2592000
38	12960000
39	17280000
40	6480000
41	518400

[1, 1, 1, 1, 2, 4, 4, 16, 4, 12, 72, 36, 36, 324, 324, 36, 144, 1728, 2592, 576, 576, 9216, 20736, 9216, 576, 2880, 57600, 172800, 115200, 14400, 14400, 360000, 1440000, 1440000, 360000, 14400, 86400, 2592000, 12960000, 17280000, 6480000, 518400]

cp's OEIS Frontend

A145891 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k adjacent pairs of the form (odd,even) (0<=k<=floor(n/2)).

Table of values

List of values