A014662 Primes p such that order of 2 mod p (=A007733(p)) is even.

3, 5, 11, 13, 17, 19, 29, 37, 41, 43, 53, 59, 61, 67, 83, 97, 101, 107, 109, 113, 131, 137, 139, 149, 157, 163, 173, 179, 181, 193, 197, 211, 227, 229, 241, 251, 257, 269, 277, 281, 283, 293, 307, 313, 317, 331, 347, 349, 353, 373, 379, 389, 397, 401, 409, 419

Offset

1,1

Comments

Apart from the first term, identical to A091317. - Charles R Greathouse IV, Feb 13 2009

References

P. Moree, Appendix to V. Pless et al., Cyclic Self-Dual Z_4 Codes, Finite Fields Applic., vol. 3 pp. 48-69, 1997.

Links

Klaus Brockhaus, Table of n, a(n) for n=1..1000

C. Smyth, The terms in Lucas Sequences divisible by their indices, JIS 13 (2010) #10.2.4.

Maple

select(t -> isprime(t) and numtheory:-order(2, t)::even, [2*i+1 $ i=1..1000]); # Robert Israel, Aug 12 2014

Mathematica

Select[Prime[Range[80]], EvenQ[MultiplicativeOrder[2, #/(2^IntegerExponent[ #, 2])]]&] (* Jean-François Alcover, Sep 02 2018 *)

Prog

(Magma) [ p: p in PrimesInInterval(3, 419) | IsEven(Modorder(2, p)) ] // Klaus Brockhaus, Dec 09 2008
(PARI) isok(p) = isprime(p) && !(znorder(Mod(2, p/2^valuation(p, 2))) % 2); \\ Michel Marcus, Sep 02 2018

Crossrefs

The prime terms of A296243.

Cf. A091317.

Sequence in context: A059315 A045403 A059641 * A059349 A045316 A040100

Adjacent sequences: A014659 A014660 A014661 * A014663 A014664 A014665

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Klaus Brockhaus, Dec 09 2008

Status

approved