A152308 - OEIS

%I #13 Nov 23 2024 11:13:06

%S 73,89,233,937,1217,1249,1289,1433,1553,1609,1721,1913,2441,2969,3257,

%T 3449,4049,4201,4273,4297,4409,4481,4993,5081,5297,5689,6089,6449,

%U 6481,6689,6857,7121,7529,7993,8081,8609,8969,9137,9281,9769,10337,10369

%N Primes p such that the multiplicative order of 2 modulo p is (p-1)/8.

%H Klaus Brockhaus, <a href="/A152308/b152308.txt">Table of n, a(n) for n=1..1000</a>

%t okQ[p_] := MultiplicativeOrder[2, p] == (p-1)/8;

%t Select[Prime[Range[2000]], okQ] (* _Jean-François Alcover_, Nov 23 2024 *)

%o (Magma) [ p: p in PrimesUpTo(10369) | r eq 1 and Order(R!2) eq q where q,r is Quotrem(p,8) where R is ResidueClassRing(p) ];

%o (PARI) Vec(select(p->((p!=2) && (znorder(Mod(2, p)) == (p-1)/8)), primes(10000))) \\ _Michel Marcus_, Feb 09 2015

%Y Cf. A115591, A001133, A001134, A001135, A001136.

%K nonn

%O 1,1

%A _Klaus Brockhaus_, Dec 02 2008