A113248 - cp's OEIS frontend

A113248 Number of permutations pi in S_n such that maj pi and maj pi^(-1) have opposite parity where maj is the major index. Equivalently, the number of pi such that maj pi and inv pi have opposite parity where inv is the inversion number.

n	a(n)
0	0
1	0
2	2
3	8
4	56
5	336
6	2496
7	19968
8	181248
9	1812480
10	19956480
11	239477760
12	3113487360
13	43588823040
14	653836861440
15	10461389783040
16	177843708887040
17	3201186759966720
18	60822550111518720
19	1216451002230374400

[0, 0, 2, 8, 56, 336, 2496, 19968, 181248, 1812480, 19956480, 239477760, 3113487360, 43588823040, 653836861440, 10461389783040, 177843708887040, 3201186759966720, 60822550111518720, 1216451002230374400]

cp's OEIS Frontend

A113248 Number of permutations pi in S_n such that maj pi and maj pi^(-1) have opposite parity where maj is the major index. Equivalently, the number of pi such that maj pi and inv pi have opposite parity where inv is the inversion number.

Table of values

List of values