A262234 - cp's OEIS frontend

A262234 Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1) if n>0.

n	a(n)
0	1
1	1
2	2
3	6
4	36
5	376
6	6040
7	137320
8	4188320
9	164844064
10	8129435904
11	490812707456
12	35601674684160
13	3054648986802432
14	305980722047302144
15	35383891435049320960
16	4678354778386866393088
17	701273672223926436540416
18	118292442535368693562662912

[1, 1, 2, 6, 36, 376, 6040, 137320, 4188320, 164844064, 8129435904, 490812707456, 35601674684160, 3054648986802432, 305980722047302144, 35383891435049320960, 4678354778386866393088, 701273672223926436540416, 118292442535368693562662912]

cp's OEIS Frontend

A262234 Number of ordered pairs (p,q) of permutations of [n] with equal up-down signatures and p(1)=q(1) if n>0.

Table of values

List of values