Sum of n terms of the series `1,3,7,15,31,......` is

Sum of n terms of the series 1,3,7,15,31,dots... is

sum on n terms of the series 3,7,11,15,...... is

Sum to n terms of the series 1+3+7+13+.. .=

Sum to n terms the series 1+3+7+15+31+...

Sum to n terms the series 1+3+7+15+31+...

Sum to n terms the series 1+3+7+15+31+...

Sum to n terms of the series 3+15+35+63+.. ..

Sum of first n terms of the series 1+3+5+7+.... is 100. If 3 consecutive terms be removedfrom these n terms then sum of the remaining terms and sum of original terms are in the ratio 17:20. Which of the following is/are correct.

Find the sum to n terms of the series 5,7,13,31,85+…….