cp's OEIS Frontend

A269728 Let k be a number not a power of 2 (see A057716), and define r by 2^(r-1) < k < 2^r; a(n) is smallest prime of the form 2^r*m+1 such that the exponential sum S(sigma_{m,k}) avoids p.

%I A269728 #10 Mar 08 2016 10:11:20
%S A269728 5,17,41,73,97,17,17,17,17,17,17,1601,97,97,449,257,97,97,97,97,193,
%T A269728 257,97,97,97,449,193,1409,193,193,193,257,193,449,769,257,193,449,
%U A269728 257,193,193,193,193,257,449,193,193,193,257,449,257,257,257,449,641
%N A269728 Let k be a number not a power of 2 (see A057716), and define r by 2^(r-1) < k < 2^r; a(n) is smallest prime of the form 2^r*m+1 such that the exponential sum S(sigma_{m,k}) avoids p.
%C A269728 See Castro-Medina (2016) for precise definition.
%C A269728 It is only a conjecture that this sequence is infinite.
%H A269728 Francis N. Castro and Luis A. Medina, <a href="http://arxiv.org/abs/1603.00534">Modular periodicity of exponential sums of symmetric Boolean functions and some of its consequences</a>, arXiv:1603.00534 [math.NT], 2016.
%Y A269728 Cf. A057716.
%K A269728 nonn
%O A269728 1,1
%A A269728 _N. J. A. Sloane_, Mar 08 2016