A005283 - cp's OEIS frontend

A005283 Number of permutations of (1,...,n) having n-5 inversions (n>=5).

n	a(n)
5	1
6	5
7	20
8	76
9	285
10	1068
11	4015
12	15159
13	57486
14	218895
15	836604
16	3208036
17	12337630
18	47572239
19	183856635
20	712033264
21	2762629983
22	10736569602
23	41788665040
24	162869776650
25	635562468075
26	2482933033659
27	9710010151831
28	38008957336974
29	148912655255315
30	583885852950802

[1, 5, 20, 76, 285, 1068, 4015, 15159, 57486, 218895, 836604, 3208036, 12337630, 47572239, 183856635, 712033264, 2762629983, 10736569602, 41788665040, 162869776650, 635562468075, 2482933033659, 9710010151831, 38008957336974, 148912655255315, 583885852950802]

cp's OEIS Frontend

A005283 Number of permutations of (1,...,n) having n-5 inversions (n>=5).

Table of values

List of values