Narrowest N Bars

The indicator is inspired by Toby Crabel's work.
Originally 2-Bar NR pattern is defined as the narrowest range from high to low of any two day period relative to any two day period within the previous 20 market days.

However, this script allows user to look for N Bar narrowest range within user defined numbers of previous days

Settings are as follows:
1. N Bars - sets number of bars in range
2. Lookback period is self-descriptive)

The last bar in the narrowest range is marked with N