Find the sum of the series `2/9 + 1/3 + 1/2 + ……… +(81)/(32)`

Find the sum of the series : 1+ 2/3+1/3+0 +…….. To 19 terms.

Find the sum of the series 1^2+3^2+5^2+ ton terms.

Find the sum of the series : 3+6+9+12……………… to 40 terms .

Find the sum of the series (1^(2)+1)1!+(2^(2)+1)2!+(3^(2)+1)3!+ . .+(n^(2)+1)n! .

Find the sum of the series : tan^- 1(1/3)+tan^- 1(2/9)+....+tan^- 1((2^(n-1))/(1+2^(2n-1)))+...... oo

Find the sum of the series (1^3)/1+(1^3+2^3)/(1+3)+(1^3+2^3+3^3)/(1+3+5)+ up to n terms.

Find the sum to n terms of the series (1)/(1*3*5*7*9)+(1)/(3*5*7*9*11)+(1)/(5*7*9*11*13)+"......" . Also, find the sum to infinty terms.