MATLAB: How to write an efficient script for perfect numbers

homework

I have to display the first 4 perfect numbers but am running into a problem. The way I am trying it takes very very long to reach the last value (8128 or whatever). Figured out how to post code (there's a freaking button for it lol…)
for k = 1:9000
  factors = divisors(k);
  factors(end) = [];
  if sum(factors) == k
      disp(k)
end

Best Answer

Try this:
for k = 1:9000
    % factors = divisors(k);
    D = 1:k ;
    factors =D(rem(k,D)==0) ;
    factors(end) = [] ;
    if sum(factors) == k
        disp(k)
    end
end
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