A122923 Express n as the sum of four squares, x^2+y^2+z^2+w^2, x>=y>=z>=w>=0, sequentially minimizing the value of x, y and z. a(n) is that z.

0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 3, 0, 2, 3, 3, 3, 2, 3, 2, 2, 3, 3, 3, 3, 3, 2, 3, 4, 4, 3, 3, 4, 2, 3, 2, 2, 4, 4, 3, 3, 4, 3, 3, 4, 3, 4, 4, 3, 4, 4, 3, 4, 4, 3, 4, 5, 4, 4, 5, 2, 4, 4, 3, 5, 3, 4, 5, 4, 4, 5, 5, 4, 4, 4, 5, 4, 4, 5, 4, 5, 5, 5, 5, 4