38896200domain: NAppears in sequencesLet M_n be the n X n matrix with M_n(i,j)=i^3/(i+j); then a(n)=1/det(M_n).at n=4A069649a(n) is the least integer k such that the sum of the prime divisors of k, each taken modulo its exponent in the prime factorization of k, equals n.at n=9A391646