A316775 - cp's OEIS frontend

A316775 a(n) is the number of permutations of [1..n] that have the same number of inversions as non-inversions.

n	a(n)
0	1
1	1
2	0
3	0
4	6
5	22
6	0
7	0
8	3836
9	29228
10	0
11	0
12	25598186
13	296643390
14	0
15	0
16	738680521142
17	11501573822788
18	0
19	0
20	62119523114983224
21	1214967840930909302
22	0
23	0
24	12140037056605135928410
25	285899248139692651257566
26	0
27	0
28	4759461354691529363949651814

[1, 1, 0, 0, 6, 22, 0, 0, 3836, 29228, 0, 0, 25598186, 296643390, 0, 0, 738680521142, 11501573822788, 0, 0, 62119523114983224, 1214967840930909302, 0, 0, 12140037056605135928410, 285899248139692651257566, 0, 0, 4759461354691529363949651814]

cp's OEIS Frontend

A316775 a(n) is the number of permutations of [1..n] that have the same number of inversions as non-inversions.

Table of values

List of values