Number of degree-2n permutations without odd cycles and such that number of cycles of size 2k is odd (or zero) for every k.

A130644

Number of degree-2n permutations without odd cycles and such that number of cycles of size 2k is odd (or zero) for every k.

Terms

    a(0) =1a(1) =1a(2) =6a(3) =225a(4) =8400a(5) =760725a(6) =91725480a(7) =15563633085

External references