A268536 - cp's OEIS frontend

A268536 The number of permutations of {1,2,...,n,1,2,...,n} with the property that there are k numbers between the two k's in the set for k=1,...,n, as n runs through the positive integers congruent to -1 or 0 mod 4.

n	a(n)
1	2
2	2
3	52
4	300
5	35584
6	216288
7	79619280
8	653443600
9	513629782560
10	5272675722400
11	7598911885030976
12	93690316113031872
13	223367222197529806464
14	3214766521218764786304

[2, 2, 52, 300, 35584, 216288, 79619280, 653443600, 513629782560, 5272675722400, 7598911885030976, 93690316113031872, 223367222197529806464, 3214766521218764786304]

cp's OEIS Frontend

A268536 The number of permutations of {1,2,...,n,1,2,...,n} with the property that there are k numbers between the two k's in the set for k=1,...,n, as n runs through the positive integers congruent to -1 or 0 mod 4.

Table of values

List of values