Theorem 2.1. The solutions to the Diophantine equation 2x + 3y2 = 4z in non-negative integers are given by
(x; y; z) 2 f(2(n ¡ 1); 0; n ¡ 1) : n 2 Ng [ f(2(n ¡ 1); 2n¡1; n) : n 2 Ng:
Proof. We ¯rst consider the case when z = 0; obtaining 2x + 3y2 = 1 in which we may deduce immediately that
x = 0 and y = 0: For the case x = 0; we have 4z ¡ 3y2 = 1: This is true only when z = 0, y = 0 and y = 1, z = 1:
On the other hand, if y = 0, we have 2x = 22z; or equivalently x = 2z: Now for the general case, x; y; z > 0; we
have 22z ¡ 2x = 3y2: Then, 2x(22z¡x ¡ 1) = 3y2: Hence, 2x = y2 and 22z¡x ¡ 1 = 3: The latter equation is true
for x = 2(z ¡ 1), and 2x = y2 is satis¯ed for all x = 2(n ¡ 1) and y = 2n¡1, where n is a natural number. Also, it
follows that z = n: This proves the theorem.