Find the sum to n terms of the following series :
`(1) + (1+3) + (1+3+3^(2)) +…`

Find the sum of n terms of the following series : 1+3+7+13 +......

Find the sum to n terms of each of the following series : (1) + (1+2) + (1+2+3)+…

Find the sum to n terms of the following series : 1+2a + 3 a^(2) + 4a^(3) + …, [a != 1]

Find the sum to n terms of each of the following series : (1)/(1.3) + (1)/(3.5) + (1)/(5.7) +…

Find the sum of first n term of the following series 1+(1+3)+(1+3+3^2)+ ….

Find the sum of first n terms of the following series : 1.2^(2) + 2.3^(2) + 3.4^(2)+…

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

Find the sum to n terms of each of the following series : n.1 + (n-1).2+(n-2). 3+(n-3).4+…

Find the sum to n terms of the following (1-2) series: (i) 1+3/2+5/(2^(2))+7/(2^(3))+ ………….. (ii) 1+2/3+3/(3^(2))+4/(3^(3))+ …………