The sum to 50 terms of the series
`3/1^2+5/(1^2+2^2)+7/(1^+2^2+3^2)+….+… is `

Find the sum to n terms of each of the series in 1^2 + (1^2 + 2^2) + (1^2 + 2^2 + 3^2) + ...

Find the sum to n terms of each of the series in 3 × 1^(2) + 5 × 2^(2) + 7 × 3^(2) +.........

Find the sum to n terms of the series 3//(1^2xx2^2)+5//(2^2xx3^2)+7//(3^2xx4^2)+dot

Find the sum of the firt 40 terms of the series 1^(2) -2^(2) + 3^(2) - 4^(2) +……….

Find the sum to n terms of the series: 1/(1+1^2+1^4)+1/(1+2^2+2^4)+1/(1+3^2+3^4)+

The sum up to 10 terms of the series (3 xx 1^(3))/(1^(2)) + (5 xx (1^(3) + 2^(3)))/(1^(2) + 2^(2)) + (7 xx (1^(3) + 2^(3) + 3^(3)))/(1^(2) + 2^(2) + 3^(2)) + ....

Find the sum to n terms of the series 1^2+2^2+3^2-4^2+5^2-6^2+. . . .

The sum of the first 9 terms of the series 1^3/1 + (1^3 + 2^3)/(1+3) + (1^3 + 2^3 +3^3)/(1 + 3 +5) ..... is :

The sum to first 25 terms of the series 1+2+3+"…………" is