A225108 - cp's OEIS frontend

A225108 Number of pairs (x,y) of elements x of the symmetric group S_{n-1} and y of the symmetric group S_{n} that commute. Here the symmetric group S_{n-m} is to be thought of as the subgroup of the symmetric group S_n which stabilizes n-m+1,n-m+2,...n.

n	a(n)
1	1
2	2
3	8
4	42
5	288
6	2280
7	21600
8	226800
9	2701440
10	35199360
11	504403200
12	7783776000
13	130288435200
14	2322678758400
15	44286571929600
16	894449267712000
17	19144352747520000
18	431093162852352000
19	10224590808047616000
20	253873324553232384000
21	6602896050191400960000

[1, 2, 8, 42, 288, 2280, 21600, 226800, 2701440, 35199360, 504403200, 7783776000, 130288435200, 2322678758400, 44286571929600, 894449267712000, 19144352747520000, 431093162852352000, 10224590808047616000, 253873324553232384000, 6602896050191400960000]

cp's OEIS Frontend

A225108 Number of pairs (x,y) of elements x of the symmetric group S_{n-1} and y of the symmetric group S_{n} that commute. Here the symmetric group S_{n-m} is to be thought of as the subgroup of the symmetric group S_n which stabilizes n-m+1,n-m+2,...n.

Table of values

List of values