for (int i=1;i<100000;i=2*i)

def loopByTwiceBefore(from:Int, to:Int)(f:Int=>Unit):Unit = {
    if (from<to){
        f(from)
        loopByTwiceBefore(from*2, to)(f);
    }
  }

Iterator.iterate(1)(_*2).takeWhile(_ < 100000) foreach {...}