function chazhao(a)
k=0;
for i=2:a;
    for j=1:i;
        if panhushu(i,j)~=1;
            if rem(i,2)==0;
                if rem(j,2)==1;
                    k=k+1;
                    x=2*i*j;
                    y=i^2-j^2;
                    z=i^2+j^2;
                    fprintf('%d %d^2+%d^2=%d',k,x,y,z);
                end
            else
                if rem(j,2)==0;
                k=k+1;
                    x=2*i*j;
                    y=i^2-j^2;
                    z=i^2+j^2;
                    fprintf('%d %d^2+%d^2=%d',k,x,y,z);
                end
            end
        end
    end
end
%disp('error');