A127438 Minimal nonnegative solution to 2^x == 3 (mod p) where p goes over primes for which such a solution exists (A001915).

0, 3, 8, 4, 13, 8, 5, 26, 19, 17, 50, 6, 39, 16, 72, 19, 69, 70, 72, 41, 87, 101, 48, 27, 108, 56, 89, 42, 181, 43, 46, 48, 83, 109, 157, 93, 92, 56, 249, 152, 26, 69, 238, 137, 184, 271, 11, 100, 404, 13, 318, 111, 450, 25, 320, 151, 130, 9, 297, 104, 429, 435, 530, 105, 478, 175, 114, 75, 175, 80

Offset: 1

Author

Max Alekseyev, Jan 14 2007

Keywords

• nonn

Crossrefs

Cf. A001915.

Programs

Magma

lst:=[0]; for p in [5..647 by 2] do if IsPrime(p) then e:=Ceiling(Log(2, p+1)); for x in [e..p-2] do if 2^x mod p eq 3 then Append(~lst, x); break; end if; end for; end if; end for; lst; // Arkadiusz Wesolowski, Jan 12 2021

Formula

2^a(n) == 3 (mod A001915(n)), where a(n) >= 0 and minimum possible.

Extensions

Corrected by Max Alekseyev, Jun 08 2011

Corrected by Arkadiusz Wesolowski, Jan 12 2021