A309807 - cp's OEIS frontend

A309807 Number of permutations sigma of [n] such that sigma(k)/k > sigma(k+1)/(k+1) for 1 <= k <= n-1.

n	a(n)
0	1
1	1
2	1
3	2
4	3
5	6
6	9
7	19
8	30
9	60
10	108
11	222
12	388
13	874
14	1601
15	3244
16	6437
17	14056
18	26545
19	57326
20	109333
21	232751
22	481137
23	1002039
24	1911740
25	4261276
26	8678424
27	17734328
28	36186279
29	77402058
30	154454851
31	340848002
32	691228119
33	1460761640

[1, 1, 1, 2, 3, 6, 9, 19, 30, 60, 108, 222, 388, 874, 1601, 3244, 6437, 14056, 26545, 57326, 109333, 232751, 481137, 1002039, 1911740, 4261276, 8678424, 17734328, 36186279, 77402058, 154454851, 340848002, 691228119, 1460761640]

cp's OEIS Frontend

A309807 Number of permutations sigma of [n] such that sigma(k)/k > sigma(k+1)/(k+1) for 1 <= k <= n-1.

Table of values

List of values