A321313 - cp's OEIS frontend

A321313 Number of permutations of [n] with equal lengths of the longest increasing subsequence and the longest decreasing subsequence.

n	a(n)
1	1
2	0
3	4
4	4
5	36
6	256
7	1282
8	9864
9	99976
10	970528
11	9702848
12	113092200
13	1500063930
14	20985500212
15	305177475748
16	4733232671056
17	79461918315024
18	1427464201289584
19	26955955609799728
20	531536672155429792
21	10980840178654738496
22	238597651836121062824
23	5446220581860028853936

[1, 0, 4, 4, 36, 256, 1282, 9864, 99976, 970528, 9702848, 113092200, 1500063930, 20985500212, 305177475748, 4733232671056, 79461918315024, 1427464201289584, 26955955609799728, 531536672155429792, 10980840178654738496, 238597651836121062824, 5446220581860028853936]

cp's OEIS Frontend

A321313 Number of permutations of [n] with equal lengths of the longest increasing subsequence and the longest decreasing subsequence.

Table of values

List of values