The sum of the first n terms of the series `1^2+ 2.2^2+3^2 +2.4^2+....` is `(n(n+1)^2)/2` when n is even. Then the sum if n is odd , is

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

The sum of 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))/(2) when n is even.when n is odd the sum is

Find the sum of n terms of the series 1.2^(2)+2.3^(2)+3.4^(2)+

The sum to n term of the series 1(1!)+2(2!)+3(3!)+