Error writing to text file

Below is the code I am having issues with. The values for t and Q that are being writing onto the text file are wrong and I am not sure how to fix this.

fid= fopen('RCSimulation.txt','w');
fprintf(fid, '%%  Time \t   Q \t   V \t   i \n');
fprintf(fid, '%%  (s) \t   (C) \t   (V) \t   (Ohm) \n');
fprintf(fid, '%%  ==== \t   ==== \t   ==== \t   ==== \n');
for n=1:N
    t(n+1)=t(n)+Dt; % Updates time vector
    Q(n+1)=Q(n)+Dt*Qdot(t(n),Q(n)); % Calls the function f(t,Q) = Qdot
    fprintf(fid,'   %4.1f \t %6.1f \n', t, Q);

end
fclose(fid);

[Guillaume]

So, what is being written and what should be written?

What is the contents of t and Q at the end of the loop? What is in written in the file?

[Jan]

Please describe the issus you have. It is easier to solve a problem than to guess, what the problem ist.