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%I #11 Oct 10 2024 15:09:21
%S 1163,1709,2003,3109,3389,3739,5237,5531,5867,7309,9157,9829,10627,
%T 10739,11117,11243,11299,11411,11467,13259,18803,20147,20483,21323,
%U 21757,27749,27763,29947,30773,31123,31627,32803,33461,33587,34469
%N Primes p such that the multiplicative order of 2 modulo p is (p-1)/7.
%H Klaus Brockhaus, <a href="/A152307/b152307.txt">Table of n, a(n) for n=1..1000</a>
%t Select[Prime[Range[4000]],MultiplicativeOrder[2,#]==(#-1)/7&] (* _Harvey P. Dale_, Oct 10 2024 *)
%o (Magma) [ p: p in PrimesUpTo(34469) | r eq 1 and Order(R!2) eq q where q,r is Quotrem(p,7) where R is ResidueClassRing(p) ];
%o (PARI) Vec(select(p->((p!=2) && (znorder(Mod(2, p)) == (p-1)/7)), 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