A108600 - cp's OEIS frontend

A108600 Number of freely braided permutations of length n; the freely braided permutations are those that avoid 3421, 4231, 4312 and 4321.

n	a(n)
0	1
1	1
2	2
3	6
4	20
5	71
6	260
7	971
8	3674
9	14032
10	53968
11	208692
12	810492
13	3158760
14	12346628
15	48377494
16	189952216
17	747180999
18	2943648824
19	11612917815
20	45869337526
21	181372345723
22	717856746216
23	2843678131629
24	11273602645942
25	44725291921541
26	177551518494116
27	705264937798343

[1, 1, 2, 6, 20, 71, 260, 971, 3674, 14032, 53968, 208692, 810492, 3158760, 12346628, 48377494, 189952216, 747180999, 2943648824, 11612917815, 45869337526, 181372345723, 717856746216, 2843678131629, 11273602645942, 44725291921541, 177551518494116, 705264937798343]

cp's OEIS Frontend

A108600 Number of freely braided permutations of length n; the freely braided permutations are those that avoid 3421, 4231, 4312 and 4321.

Table of values

List of values