`1+3+7+15+31+...+ ` to n terms

Find the sum of the series 3 + 7 + 13 + 21 + 31 + … to n terms . Find the sun when n=20

Find the sum of the series 3 + 7 + 13 + 21 + 31 + … to n terms . Find the sun when n=20

Sum of the series 1+3+7+15+....... upto n terms.

1+ 3+ 7 + 15… n terms =

1/2+3/4+7/8+15/16+..... t o n terms =

Find the sum of the following series : 3.1^2+5.2^2+7.3^2 + .... to n terms .

lim_(n to infty) ((1)/(3.7)+(1)/(7.11) +(1)/(11.15)+. . . +(n" terms ")) =

Find the sums of the indicated number of terms of the following geometric progressions : 1,1/3,1/9 .........., n terms, 5 terms.