The sum of series `1+3/(2!)+7/(3!)+15/(4!)+...........oo` is equal to :

The sum of series (2)/(3!)+(4)/(5!)+(6)/(7!)+..........oo is :

The sum of series 2/(3!)+4/(5!)+6/(7!)+...........oo is :

The sum of the series 5/(1. 2.3)+7/(3. 4.5)+9/(5. 6.7)+ ....is equal to

The sum of the series (1)/(1*2)-(1)/(2*3)+(1)/(3*4)--- upto oo is equal to

find the sum of 15 terms of The sum of the series (1)/(3)+(1)/(15)+(1)/(35)+(1)/(63)+..........oo terms,is

The sum of the series (5)/(1.2.3)+(7)/(3.4.5)+(9)/(5.6.7)+.... is equal to

The sum of the first n terms of the series (1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+.... is equal to

The sum of the first n terms of the series (1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+.... is equal to