68510domain: NAppears in sequencesa(n) = Sum of all divisors of all numbers < (n+1)^2.at n=15A168013a(1)=2; for n > 1, a(n) is the largest number <= 2*a(n-1) divisible by n.at n=16A178901a(n) = 2*n^3 + 9*n^2 + 9*n.at n=31A303609a(n) = (2n^2 - n + 2) * (2n)! / ((n + 1) * (n + 2) * n!^2).at n=8A349695