How to find asymptotically (or some reasonable bound, at least $ o(n) $) number of numbers, representable as a sum of squares of 2 numbers? (in case of bound I am interested in both: lower and upper bounds)
I know how to find explicitly the number of ways to represent given number in such a way. (can be found here)
Thank you!
P.S. For one lower bound you can use this problem, it'll give you somewhat $ \Omega (n^{\frac{3}{4}}) $.