651420domain: NAppears in sequencesa(n) = lcm(1,2,3,...,n) * (sum of Farey fractions of order n).at n=11A093627Numbers expressible in more than one way as 6^x-y^2.at n=33A134989a(1) = 252, a(n) is a(n-1) multiplied by the smallest prime factor of a(n-1)+1.at n=3A152466