Writing data to a file

I'd like write 1 to 20 to a file, but not sure how I would go about finishing the code. I've attempted to use a for loop here and think this is the right approach as it does count from 1 to 20, but the end of my code looks like this...

And I'd like to remove the two ans, but have tried to put semi colons in different places to hide the ans and doesn't seem to work. Here is my (attempted) code:

fileid= fopen('data.dat','w')
for a = 1.0:1:20;
    disp(a)
end
fprintf(fileid,'%s',a)
fclose(fileid)

Answer 1

[Bhaskar R]

fileid= fopen('data.dat','w');
fprintf(fileid, '%d\n', [1:20]');
fclose(fileid)

[Millie Jones]

Thank you :-) That makes a lot more sense, I realised I wasn't actually writing anything to my file