Calculus 2 sequence of natural numbers expressions

Question

a(n)=2^n2 +1 for n belonging to natural numbers N. Compute the following expressions 

1) a _n*4

2) a* (n • a* a * 3)

3) a*(a * a * i) 

*means sub

I’m so lost. 

I thought maybe it was asking for a sequence of {1,2,3,4...} where n is a natural number So 

But what do I do when it starts with the a(n*4) and the other ones? What is it asking for? 

a(n* 4)= (2^n2 +1)^4. ?

Answer 1

I think your problem is the notation, which is certainly unclear.

I think what you mean (given the limitations of this editor) is

x(n)=n² + 1 and a(n) = 2^x(n).

Then the notation in the questions is totally unclear. In order to answer these questions, I think you need to be clear about the notation.