This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A152308 #13 Nov 23 2024 11:13:06 %S A152308 73,89,233,937,1217,1249,1289,1433,1553,1609,1721,1913,2441,2969,3257, %T A152308 3449,4049,4201,4273,4297,4409,4481,4993,5081,5297,5689,6089,6449, %U A152308 6481,6689,6857,7121,7529,7993,8081,8609,8969,9137,9281,9769,10337,10369 %N A152308 Primes p such that the multiplicative order of 2 modulo p is (p-1)/8. %H A152308 Klaus Brockhaus, <a href="/A152308/b152308.txt">Table of n, a(n) for n=1..1000</a> %t A152308 okQ[p_] := MultiplicativeOrder[2, p] == (p-1)/8; %t A152308 Select[Prime[Range[2000]], okQ] (* _Jean-François Alcover_, Nov 23 2024 *) %o A152308 (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 A152308 (PARI) Vec(select(p->((p!=2) && (znorder(Mod(2, p)) == (p-1)/8)), primes(10000))) \\ _Michel Marcus_, Feb 09 2015 %Y A152308 Cf. A115591, A001133, A001134, A001135, A001136. %K A152308 nonn %O A152308 1,1 %A A152308 _Klaus Brockhaus_, Dec 02 2008