  We discuss the problem of finding distinct integer sets $\{x_1,x_2,...,x_n\}$
where each sum $x_i+x_j, i \ne j$ is a square, and $n \le 7$. We confirm
minimal results of Lagrange and Nicolas for $n=5$ and for the related problem
with triples. We provide new solution sets for $n=6$ to add to the single known
set. This provides new information for problem D15 in Guy's {\it Unsolved
Problems in Number Theory}
