(In reply to
re: a computerized start but no proof and too small a sample size by Jer)
P^2=28Q^2+1 is a pell equation when put in the form
P^228Q^2=1
and there are established methods for finding all solutions to these types of equations (just google pell equation). In fact the method of solution is to find a recurrence relation like you did. So it is fairly easy to establish that your recurrence denotes all of the solutions. The hard part is the inductive proof which I as well have been attempting with no success

Posted by Daniel
on 20100503 10:31:08 