Discrete Fourier Transform MATLAB Code

This code computes the DFT from time domain.

Can anybody see the code below and help me to get the right answer?

my problem is:

when I change N value, for example, to 4, 5, 10 ,or other values.

X(1) changes with that. but I think X(1) must be the same for every value of N.

just like the shape below: the N value changes but the vertical value is the same.

I appreciat if you help me.

Thank you.

clear; clc;
% %%  Analytical
N=4;
k=0:N-1;
X=zeros(N,1);
t=k/N;

%x=5+2*cos(2*pi*t-pi/2)+3*cos(4*pi*t)
x=abs((1-(0.012.*(pi.*52.*(t-0.3721)).^2)).*exp(-(pi.*52.*(t-0.3721).^2)))
sum(x)/N

for k=0:N-1
    for n=0:N-1
        X(k+1)=X(k+1)+x(n+1)*-i^(n*k)/N;
    end
end

k1=[0:N-1];
stem(k1,abs(X))
% xlim([0 1])
% ylim([-1 1])