The a16z podcast is available via the iTunes podcasts feed: https://itunes.apple.com/us/podcast/a16z/id842818711?mt=2

Which means you can also add it in Overcast, or the Pocket Casts player and play it via the web:

https://play.pocketcasts.com/web/podcasts/index#/podcasts/sh...

https://overcast.fm/itunes842818711/a16z