Nice.
A numeric example for 2n1 = 65:
https://www.wolframalpha.com/input/?...er+the+integer
ETA:
No solutions for 2n1 = 21 even though it is of the form 4m+1 since it has at least one prime factor of the form 2m+1 with odd m:
https://www.wolframalpha.com/input/?...er+the+integer
Last fiddled with by a1call on 20210508 at 16:44
