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 A014659 #24 Feb 18 2021 01:32:24
%S A014659 7,15,21,23,31,35,39,45,47,49,51,55,63,69,71,73,75,77,79,85,87,89,91,
%T A014659 93,95,103,105,111,115,117,119,123,127,133,135,141,143,147,151,153,
%U A014659 155,159,161,165,167,175,183,187,189,191,195,199,203,207,213,215,217,219
%N A014659 Odd numbers that do not divide 2^k + 1 for any k >= 1.
%C A014659 This is the subset of odd integers > 1 as (2*n - 1) in A179480 such that A179480(n) is even. Example: A179480(18) = 6, even; corresponding to (2*18 - 1), 35. Then 35 is in A014659. A014657 is the subset of odd terms > 1 corresponding to odd terms in A179480. - _Gary W. Adamson_, Aug 20 2012
%C A014659 From _Wolfdieter Lang_, Aug 22 2020: (Start)
%C A014659 These odd numbers are the moduli named 2*n+1 in the definition of A003558(n), for n >= 1, for which the + sign applies. The signs in the definition of A003558 are given in A332433.
%C A014659 These are the odd numbers N >= 3 for which A003558((N-1)/2) = A002326((N+1)/2), the period length P(N) of the cycles {2^k (mod N)}_{k=0}^(P(N)-1). Compare the periods given in A201908((N+1)/2, k). (End)
%H A014659 T. D. Noe, <a href="/A014659/b014659.txt">Table of n, a(n) for n = 1..1000</a>
%H A014659 P. Moree, <a href="https://doi.org/10.1006/ffta.1996.0172">Appendix B</a>, to V. Pless et al., Cyclic Self-Dual Z_4 Codes, Finite Fields Applic., vol. 3 pp. 48-69, 1997.
%Y A014659 Cf. A179480, A002326, A003558, A201908, A332433.
%Y A014659 Cf. A014657, numbers that divide 2^k + 1 for some k.
%K A014659 nonn
%O A014659 1,1
%A A014659 _N. J. A. Sloane_
%E A014659 More terms from _Don Reble_, Nov 03 2001