Let the sum of squares function denote the number of representations of by squares, then the summatory function of has the asymptotic expansion
(1)
|
where
(2)
| |||
(3)
| |||
(4)
| |||
(5)
|
(OEIS A241017) is the Sierpiński constant (Finch 2003, p. 123), is the Dirichlet beta function, is the Euler-Mascheroni constant, and is the gamma function.