We derive the following asymptotic formula '₍ ₗr (n) r (n+1) = x (x) ^{-3/4} (c+o (1) ), x +, where r (n) is the number of representations of n as a sum of two squares, c is a positive constant, and the prime indicates summation over those n for which r (n+1) 0.
Vitalii V. Iudelevich (Thu,) studied this question.