A381531 - cp's OEIS frontend

A381531 Number of permutations of [n] having the maximal possible number of pairs of integers i in [n] such that their cycle minima have opposite sorting order.

n	a(n)
0	1
1	1
2	2
3	1
4	4
5	5
6	2
7	14
8	34
9	34
10	12
11	132
12	540
13	1020
14	888
15	288
16	4608
17	28800
18	89280
19	143712
20	113472
21	34560
22	760320
23	6773760
24	31449600
25	81527040
26	117089280
27	85847040
28	24883200
29	721612800
30	8709120000
31	56783462400
32	217205452800
33	495200563200
34	651939840000
35	450584985600
36	125411328000

[1, 1, 2, 1, 4, 5, 2, 14, 34, 34, 12, 132, 540, 1020, 888, 288, 4608, 28800, 89280, 143712, 113472, 34560, 760320, 6773760, 31449600, 81527040, 117089280, 85847040, 24883200, 721612800, 8709120000, 56783462400, 217205452800, 495200563200, 651939840000, 450584985600, 125411328000]

cp's OEIS Frontend

A381531 Number of permutations of [n] having the maximal possible number of pairs of integers i in [n] such that their cycle minima have opposite sorting order.

Table of values

List of values