A212418 - cp's OEIS frontend

A212418 Size of the equivalence class of S_n containing the identity permutation under transformations of positionally adjacent elements of the form abc <--> acb <--> cba where a

n	a(n)
0	1
1	1
2	1
3	3
4	9
5	54
6	285
7	2160
8	15825
9	151200
10	1411095
11	16329600
12	185067855
13	2514758400
14	33530101605
15	523069747200
16	8020402655265
17	141228831744000
18	2447966414868975
19	48017802792960000
20	928344187296100575
21	20071441567457280000
22	428190753438433910925

[1, 1, 1, 3, 9, 54, 285, 2160, 15825, 151200, 1411095, 16329600, 185067855, 2514758400, 33530101605, 523069747200, 8020402655265, 141228831744000, 2447966414868975, 48017802792960000, 928344187296100575, 20071441567457280000, 428190753438433910925]

cp's OEIS Frontend

A212418 Size of the equivalence class of S_n containing the identity permutation under transformations of positionally adjacent elements of the form abc <--> acb <--> cba where a

Table of values

List of values