[valtron]

A first approximation for a strategy would be to follow a boustrophedon, and keep 2, 4 and 8 near the top, e.g. something like this:

    .   .   .   .
    .   4   2   .
    8  16  32   .
  512 256 128  64

[laumars]

This is what I tried to do, but you need to get the timing perfect after doubling up the right hand 64 to link that left 3 times. So perfect, in fact, that you'll only manage it roughly every other time:

https://news.ycombinator.com/item?id=7436184