322245domain: NAppears in sequencesNumber of degree-n permutations such that number of cycles of size 2k is odd (or zero) for every k.at n=9A130275a(n) = -Sum_{0<=i<j<=n} (-1)^(i+j) * (i+j)!/(i!*j!).at n=11A306409Odd numbers k such that A380845(k) > 2*k.at n=0A380932Odd terms in A381071.at n=0A381072