No.
Justification:
Consider the positive integer 3q + 1, where q is a natural number.
(3q + 1)2 = 9q2 + 6q + 1
= 3(3q2 + 2q) + 1
= 3m + 1, (where m is an integer which is equal to 3q2 + 2q.
Thus (3q + 1)2 cannot be expressed in any other form apart from 3m + 1.