Write the first five terms of each of the sequences and obtain the corresponding series

Write the first five terms of each of the sequences in Exercises 11 to 13 and obtain the corresponding series:

Answer -11 

put n = 2 and  and plug the values of a1



put n = 3 and plug the value of a2


put n = 4 and plug the value of a3

plug  n = 5 and plug the value of a4


Hence, the first five terms of the sequence are 3, 11, 35, 107, and 323.
The corresponding series is 3 + 11 + 35 + 107 + 323 + …

Answer -12 

put n = 2 and  and plug the values of a1



put n = 3 and plug the value of a2


put n = 4 and plug the value of a3

plug  n = 5 and plug the value of a4

 

Answer -13 

put n = 3 and plug the value of a2

put n = 4 and plug the value of a3

plug  n = 5 and plug the value of a4