[dkopi]

This could probably be solved if Javascript had map/filter/reduce functions for iterators (and hopefully dictionaries) as well as arrays.

And of course a range(start,stop,step) iterator similar to python's range.

it would then be a matter of:

  next = range(1,40000).map(x => x * 2);

and because range would be an iterator, the only array created would be next.