%N Consider smallest m such that m^2 = x1^2 + ... + xn^2 with 0 < x1 < ... < xn. Sequence gives values of m^2.
%e a(3) = 49 = 36 + 9 + 4 is the smallest square which is the sum of three squares.
%Y Cf. A018935, A018937.
%A _N. J. A. Sloane_.
%E Corrected and extended by David W. Wilson.