On a conjecture for representations of integers as sums of squares and   double shuffle relations
  In this paper, we prove a conjecture of Chan and Chua for the number of representations of integers as sums of 8s integral squares. The proof uses a theorem of Imamo\={g}lu and Kohnen, and the double shuffle relations satisfied by the double Eisenstein series of level 2. 
Koji Tasaka
math.NT