A249561 - cp's OEIS frontend

A249561 Number of length n permutations avoiding (123,{1},{}) and (231,{},{2}).

n	a(n)
0	1
1	1
2	2
3	4
4	9
5	22
6	57
7	155
8	440
9	1299
10	3977
11	12596
12	41181
13	138711
14	480548
15	1709714
16	6238685
17	23319998
18	89199763
19	348799322
20	1393087403
21	5678298218
22	23603135064
23	99984420371
24	431347901729
25	1894074165622
26	8460557754681
27	38424506440883
28	177342850025592
29	831413025268569
30	3957592646327463

[1, 1, 2, 4, 9, 22, 57, 155, 440, 1299, 3977, 12596, 41181, 138711, 480548, 1709714, 6238685, 23319998, 89199763, 348799322, 1393087403, 5678298218, 23603135064, 99984420371, 431347901729, 1894074165622, 8460557754681, 38424506440883, 177342850025592, 831413025268569, 3957592646327463]

cp's OEIS Frontend

A249561 Number of length n permutations avoiding (123,{1},{}) and (231,{},{2}).

Table of values

List of values