The first equation is: a(sub <em>n</em>) = 8, 13, 18, 23
The second is: a(sub 1)=8 ; a(sub <em>n</em>)= a(sub <em>n</em>-1)+5 if you wish to find the second term, plug two into the equation for <em /><em>n</em> 8+5=13 to find the third, plug the second term, 13, in for <em>n.</em> 13+5=18.
Hope this helped! I know it's a bit on the late side, but at least you can get the general idea!