4667544000domain: NAppears in sequencesFor n >= 1, let M_n be the n X n matrix with M_n(i,j) = i^2/(i+j); then a(n) = 1/det(M_n). Also, a(0) = 1 by convention.at n=5A069651Duplicate of A069651.at n=5A090766a(n) = A163085(n)/n!.at n=11A216628a(n) = A163085(n)/(floor(n/2)!)^2.at n=10A216629