Sequences? Not sure why an algebraic formula is different from a recursive.

A recursive formula  can be used to find a term based upont the previous term

An algebraic formula can be used to find any term

First one

a_n  = 5  + 5(n - 1)    where n is the nth term

Second one  is a geometric series

a_n  =   3ⁿ     where n is the nth term

Last one

a_n   =       n 

             ____        where n is the nth term

              n + 1