I looked into this a few months ago. Although an initial google search may give many hits, some of the links will be for adaptors to Nikon Z, or Nikon 1, or for going the other way, Nikon lens to OM. I did read somewhere a description of why it is difficult to produce a OM -> Nikon F adaptor, but can't remember where.
There are some adaptors on eBay which require the rear part of the existing OM lens mount to be removed (with a screwdriver) before attaching the adaptor - more of a semi-permanent change of mount than a conventional adaptor.