60102domain: NAppears in sequencesa(1) = 1, a(n) = a(n-1)*n if n is a prime, a(n) = a(n-1)+ n if n is composite.at n=14A083524Averages of twin prime pairs of the form : sum of two or more consecutive squares.at n=23A174716Ratio A191650(n+1)/A191650(n).at n=28A191651Numbers k such that sigma(k) = psi(k) + phi(k).at n=16A389478