Fixed bug in calculation of full analytic solution

There was an off-by-one bug. The Epsilon^2 term was being dropped from the summations in the calculation of the full analytic solution. This only effected cases where Delta*sqrt(Lambda_U)/Epsilon < 5, i.e., when noise was extremely large - or Lambda_U extremely small.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>