A165543 - cp's OEIS frontend

A165543 Number of permutations of length n which avoid both the patterns 3241 and 4321. Or, equivalently, avoids both 1234 and 1342.

n	a(n)
0	1
1	1
2	2
3	6
4	22
5	89
6	380
7	1678
8	7584
9	34875
10	162560
11	766124
12	3644066
13	17469863
14	84324840
15	409471090
16	1998933556
17	9804748548
18	48298256084
19	238840150970
20	1185256302910
21	5900843531665
22	29464355189120
23	147522603762870
24	740471407808372
25	3725334547101464
26	18782663124890072
27	94889671255981134

[1, 1, 2, 6, 22, 89, 380, 1678, 7584, 34875, 162560, 766124, 3644066, 17469863, 84324840, 409471090, 1998933556, 9804748548, 48298256084, 238840150970, 1185256302910, 5900843531665, 29464355189120, 147522603762870, 740471407808372, 3725334547101464, 18782663124890072, 94889671255981134]

cp's OEIS Frontend

A165543 Number of permutations of length n which avoid both the patterns 3241 and 4321. Or, equivalently, avoids both 1234 and 1342.

Table of values

List of values