848612385domain: NAppears in sequencesa(n) = (1/1 + 1/2 + ... + 1/n)*lcm{1,2,...,n}.at n=20A025529a(n) = A003418(n+1)*H(n), where H(n) = 1 + 1/2 + ... + 1/n is the n-th harmonic number.at n=20A379561