As usual, Scrooge is a bit dogmatic. It doesn't matter much if R1 is anywhere from 100 to 240 Ohms. The resistor value stems from the minimum load current spec for the LM317, and to a lesser amount, that the current through R1 be large compared to the Adj pin current.
If you know a priori that the load current will always be much over the min. current specified for the LM317, then you can raise the impedance of the voltage divider. I have used as much as 1K for R1. At 1K, the regulation begins to suffer a bit, because the Adjust pin current starts approaching a larger fraction of the current through R1.