In lieu of a structural computer program to solve this, you could also use Moment Distribution.
I do not know of a handbook showing 5 span continuous beams, but maybe someone else has run across one.
If this is concrete, the ACI manual has some general equations for multiple span design, but nothing specific. They are also for uniform loads. What type of loading do you have on the beams? All uniform?
You also need to consider skip loading in multiple span situations. If this is confusing to you, you really need to engage the help of a structural engineer.
Mike McCann
MMC Engineering