Numbers n such that (2^n+1)/3 is prime, but cannot be written in the form a^2 + 3*b^2.
A216551
Numbers n such that (2^n+1)/3 is prime, but cannot be written in the form a^2 + 3*b^2.
Terms
- a(0) =5a(1) =11a(2) =17a(3) =23a(4) =101a(5) =167a(6) =191a(7) =347a(8) =701a(9) =1709a(10) =3539a(11) =5807a(12) =10691a(13) =11279a(14) =42737a(15) =83339a(16) =95369a(17) =117239a(18) =127031a(19) =267017a(20) =269987a(21) =374321a(22) =4031399
External references
- oeis: A216551