18522000domain: NAppears in sequencesInverse determinant of n X n matrix M[i,j] = i*j/(i+j-1).at n=4A120307a(n) = A163085(n)/n!.at n=10A216628Numbers k such that k and the next three numbers after k with the same prime signature as k also have the same set of distinct prime divisors as k.at n=8A340304