Thanks for your reply!
Ok I set my IP to 172.16.42.2 and tried to ping 42. It just times out.
My manual that came with the pineapple says to plug in an ethernet cable and it will assign a dhcp addressin the 172.16.42.0/24 range. It then says to go the the pineapple admin page at 172.16.42.1:1471. Or "Alternatively, you can assign your computer the static address 172.16.42.42/24. That's why I was doing it the way I was.
If I try it the way they suggested, even with a static on my PC, I can't ping 172.16.42.1.