The sum of the first n terms of the series, 12+2.22+32+2.42+52+2.62+….isn2(n+1)2, when n is even. When n is odd, the sum is
The sum of first n terms of the given series 12+2.22+32+2.42+52+2.62+.........isn(n+1)22, When n is even. When n is odd, the sum will be