A303287 - cp's OEIS frontend

A303287 Number of permutations p of [n] such that the sequence of ascents and descents of p or of p0 (if n is even) forms a Dyck path.

n	a(n)
0	1
1	1
2	1
3	2
4	8
5	22
6	172
7	604
8	7296
9	31238
10	518324
11	2620708
12	55717312
13	325024572
14	8460090160
15	55942352184
16	1726791794432
17	12765597850950
18	456440969661508
19	3730771315561300
20	151770739970889792
21	1359124435588313876
22	62022635037246022000
23	603916464771468176392

[1, 1, 1, 2, 8, 22, 172, 604, 7296, 31238, 518324, 2620708, 55717312, 325024572, 8460090160, 55942352184, 1726791794432, 12765597850950, 456440969661508, 3730771315561300, 151770739970889792, 1359124435588313876, 62022635037246022000, 603916464771468176392]

cp's OEIS Frontend

A303287 Number of permutations p of [n] such that the sequence of ascents and descents of p or of p0 (if n is even) forms a Dyck path.

Table of values

List of values