%0 Journal Article %A Lam, Peter Cho-Ho %T Representation of integers using $a^2 + b^2 - dc^2$ %J Journal of integer sequences %D 2015 %V 18 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/JIS_2015__18_8_a4/ %G en %F JIS_2015__18_8_a4