An arithmetic sequence with a third term of 8 and a constant difference of 5.

An arithmetic sequence (a_n) is as follows:

where  is the first term and d is the constant difference, 

thus, we see that the n'th term of an arithmetic sequence is 

in our particular case d=5, the third term is 8, so we have:



and the general term is ,

first term is -2, n'th term is -2+5(n-1)