Number of permutations of [2n] such that the GCD of the cycle lengths equals 2.

A346086

Number of permutations of [2n] such that the GCD of the cycle lengths equals 2.

Terms

    a(0) =0a(1) =1a(2) =3a(3) =105a(4) =4725a(5) =530145a(6) =45270225a(7) =12034447425

External references