"Enigmas y patrones de los números primos. De Goldbach a los primos gemelos", Harald Helfgott

Round-16 hunt: picked; source: named-course long-video search (r16 wave 4); channel screens (sellers/exam/re-upload/devotional/vendor/events), provenance check, vendor/seller/devotional recheck and quality tier A passed; strict per-title check + final strict pass; oEmbed verified.