In this paper we are dealing with the problem of the existence of two
divisors of (n2+1)/2 whose sum is equal to δn+ε, in the
case when δ and ε are even, or more precisely in the case in
which δ≡ε+2≡0 or 2(mod4). We will completely
solve the cases δ=2,δ=4 and ε=0