EDITED A014663

[Maximilian Hasler]

%I A014663
%S A014663 7,23,31,47,71,73,79,89,103,127,151,167,191,199,223,233,
%T A014663 239,263,271,311,337,359,367,383,431,439,463,479,487,503,
%U A014663 599,601,607,631,647,719,727,743,751,823,839,863,881,887
%N A014663 Primes p such that order of 2 mod p is odd.
%C A014663 Or, primes p which do not divide 2^n+1 for any n.
%C A014663 The possibility n=0 in the above rules out A072936(1)=2;
apart from this, A014663(n)=A072936(n+1). - M. Hasler, Dec 08 2007
%C A014663 The order of 2 mod p is odd iff 2^k=1 mod p, where
p-1=2^s*k, k odd. - M. Hasler, Dec 08 2007
%D A014663 H. H. Hasse, Ueber die Dichte der Primzahlen p, ..., Math.
Ann., 168 (1966), 19-23.
%D A014663 L. C. Lagarias, The set of primes dividing the Lucas
numbers has density 2/3, Pacific
               J. Math., 118 (1985), 449-461.
%D A014663 P. Moree, Appendix to V. Pless et al., Cyclic Self-Dual Z_4
Codes, Finite Fields
               Applic., vol. 3 pp. 48-69, 1997.
%H A014663 T. D. Noe, <a
href="http://www.research.att.com/~njas/sequences/b014663.txt">Table
               of n, a(n) for n=1..1000</a>
%F A014663 Has density 7/24 (Hasse)
%o A014663 (PARI) isA014663(p)=1!=Mod(1,p)<<((p-1)>>factor(p-1,2)[1,2])
listA014663(N=1000)=forprime(p=3,N,isA014663(p)&print1(p", ")) \\ - M.
Hasler, Dec 08 2007
%Y A014663 Complement in primes of A091317.
%Y A014663 Cf. A040098, A045315, A049564.
%Y A014663 Essentially the same as A072936 (except for missing leading term 2).
%Y A014663 Adjacent sequences: A014660 A014661 A014662 this_sequence
A014664 A014665 A014666
%Y A014663 Sequence in context: A036259 A004628 A089199 this_sequence
A007522 A098029 A098039
%K A014663 nonn
%O A014663 1,1
%A A014663 njas
%E A014663 Edited by Maximilian F. Hasler
(maximilian.hasler(AT)gmail.com), Dec 08 2007