Command to download all 16 videos for offline viewing into a separate directory indexed by video order:

youtube-dl -o '%(playlist)s/%(playlist_index)s - %(title)s.%(ext)s' https://www.youtube.com/playlist?list=PLM4u6XbiXf5rtyzi7g-5O...

On Windows, the single quotes might need to be double quotes. The above uses youtube-dl (YouTube downloader) which is a multi-platform public-domain Python program available here: https://rg3.github.io/youtube-dl/.