Question

How do you find the explicit formula for the following sequence 3, 7, 11, 15,...?

Answer 1

The general formula is `a_n=4n-1` for `n=1,2,3,...`

Explanation:

It is an arithemtic progession with first term `a_1=3` and ratio `r=4`

hence the general formula is

`a_n=a_1+(n-1)*r=>a_n=3+(n-1)*4=4*n-1`