A136007 Primes of the form 2^p - 1, where p is a prime number that is not the sum, minus 1, of a Pythagorean triple.
3, 7, 31, 127, 8191, 131071, 524287, 2147483647, 2305843009213693951, 170141183460469231731687303715884105727, 6864797660130609714981900799081393217269435300143305409394463459185543183397656052122559640661454554977296311391480858037121987999716643812574028291115057151
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..13
Programs
-
Mathematica
q[n_] := n == 2 || Module[{d = Divisors[(n+1)/2]}, AllTrue[Range[3, Length[d]], d[[#]] >= 2 * d[[#-1]] &]]; 2^Select[MersennePrimeExponent[Range[13]], q] - 1 (* Amiram Eldar, Oct 20 2024 *)
Formula
a(n) = 2^A152961(n) - 1. - Amiram Eldar, Oct 20 2024
Extensions
Extended by Ray Chandler, Dec 13 2008
Comments