What ‘s the formula for this arithmetic sequence: 1st term 5, common difference of successive terms of 3

What ‘s the formula for an arithmetic sequence with the 1st term: 5 and a common difference of successive terms of 3?

I get it that a_{n} = 3. So, is the formula for the arithmetic sequence as simple as a_{n} = a_{n} + 3 ?

plug into this formula:
a_{n}= a_1 +(n-1)d

(d= difference, so it would be 3 in this case)