6*(3*n + 1)^2 - 1
6*(3*n - 2)^2 - 1
|x+y| + |x-y| = 2 find number of integral solutions of x and y.
6*(3*n - 1)^2 - 1
½-2
find x if x=1,000,000-0.25x
½+2
2*(6*n - 1)^2 - 1
4*(3*n - 1)^2 - 1
