JEE Math Practice Question

The sum of the first n terms of the series $${1^2} + {2.2^2} + {3^2} + {2.4^2} + {5^2} + {2.6^2} + ....\,is\,{{n{{(n + 1)}^2}} \over 2}$$ when n is even. When n is odd the sum is

1. A.$${\left[ {{{n(n + 1)} \over 2}} \right]^2}$$
2. B.$${{{n^2}(n + 1)} \over 2}$$
3. C.$${{n{{(n + 1)}^2}} \over 4}$$
4. D.$$\,{{3n(n + 1)} \over 2}$$