%I

%S 1,0,0,4,0,0,16,0,9,64,0,0,49,0,0,169,0,576,289,0,0,1849,0,0,4489,0,

%T 3969,17956,0,0,6889,0,0,27889,0,69696,98596,0,0,97969,0,0,499849,0,

%U 1887876,698896,0,0,2778889,0,0,4999696,0,9696996,19998784,0,0

%N Smallest square with digit sum n (or 0 if no such square exists).

%e 16 is the smallest square with digit sum 7

%K base,easy,nonn

%O 1,4

%A _Erich Friedman_, Jul 04 2001