function s1=parag_1(a)
%Ypologismos athroismatos tetragwnwn orismenou plithous arithmwn
s1=0;
for i=1:a
s1=s1+i^2;
end

% H epalitheusi ginetai pliktrologwntas:
% y=parag_1(9)
% y =
% 285
