Not OP but it got my brain curious. Found several different sites about it, here are 2 that seem fairly reputable. Apparently a 12yr old genealogy buff did an extensive search to map the presidents and came across some connections that kept them going till they found the chain of relatives for each one.
It doesn’t seem like “put on your tin foil hat close-related”, more “if you go back far enough most of us are kin in some way related”. Though, the fact that the only one who is not related, was actually appointed instead of elected, does make it look a little weird.
https://www.geni.com/blog/look-whos-related-george-washington-and-all-the-presidents-25451.html
https://familypedia.fandom.com/wiki/Genealogical_relationships_of_Presidents_of_the_United_States
No prob Mr Maggoty. Figured I couldn’t be the only one curious, why make more folks dive down that rabbit hole.