25159680domain: NAppears in sequencesa(n) = 3*2^(n-1)*(2^n-1).at n=11A103897a(n) = 2*a(n-1) + 2*a(n-2) - 4*a(n-3) with n>2, a(0)=0, a(1)=1, a(2)=3.at n=24A135094Numbers n such that sigma(n) divides the sum of the numbers x not coprime to n, with x<=n.at n=25A239208Numbers n such that tau(n)*sigma(n) divides n^2.at n=7A245787