If you plug in n = 1, then you get 3*n+5 = 3*1+5 = 3+5 = 8. So 8 is the first term.
Repeat for n = 2 and you should get 3n+5 = 3*2+5 = 6+5 = 11. Or simply add 3 to the last term 8 to get 3+8 = 11.
Repeat for n = 3 and n = 4 to get the third and fourth terms to be 14 and 17 respectively.
Answer: The first four terms are 8, 11, 14, 17