Jan [=John] is a character who never is identified by that (or any other) name in the movie, but I'm guessing bore that name on the shooting script.

The actor matching the picture of Olaf Storm in the TMDb credits plays a strictly incidental character who multiple brief close-up flashes appear of during the Club of the Sons portion early in the film, when young men are shown at a grand outdoor stadium. The unnamed character seems to be an enthusiastic announcer, or the such, for the track event. He only appears, in quick flashes, during approx. 5 seconds of that part, but never again, anytime during the movie, as far as I could tell. (I've just finished rewatching my DVD of the 2010 restoration.)

There's somewhat of a possibility that Olaf Storm may be seen again, considerably later, as one of the young men during the Oshiwara part of the movie when Robot Maria makes her debauched debut to everyone, and we see men drooling, fighting, committing murder, etc. However, in my opinion, no one looked like Olaf Storm during that part.

Incidentally, on the 2010 restoration, when the scenes with Olaf Storm appear, for five or so seconds, during the Club of the Sons portion, are starting at 0:07:11 on the DVD counter.

Ok. When I saw the film by Moroder years back I thought Jan was Freder celebrating at the games. Jan does turn up again. He is killed later fencing. Thanks for saying who Jan was. Probably not Also, however, in the club crowd watching Maria do her very erotic dance.