Representations by octonary quadratic forms with coefficients $1$, $2$,   $3$ or $6$
  Using modular forms we determine formulas for the number of representations of a positive integer by diagonal octonary quadratic forms with coefficients $1$, $2$, $3$ or $6$. 
Ay\c{s}e Alaca and M. Nesibe Kesicio\u{g}lu
math.NT