euler1.m

关于质数的一些程序

%Euler: If k is a prime, then  x^2+x+k (x=0~k-2) will always be 
%prime. Using the code below, I found it is not right.
function y=euler1(n)
m=1;
for k=2:n
    if(isprime(k))   
        p=0;
        for x=0:k-2       
            if(isprime(x^2+x+k)) y(m,x+1)=x^2+x+k;
            else y(m,x+1)=0;p=p+1;
            end
            z(m,1)=k;z(m,2)=p;
        end
        for x=k-1:n-2
            y(m,n-1)=0; %zero padding
        end   
        m=m+1;
    end
end
disp('wrong number relating to a prime:')
z %the number of the k th prime's functions x^2+x+k (x=0~k-2) 
%which are not prime.