cp's OEIS Frontend

A338062 Numbers k such that the Enots Wolley sequence A336957(k) is odd.

%I A338062 #15 Nov 06 2020 06:16:19
%S A338062 1,4,5,8,9,12,13,16,17,20,21,24,25,28,29,32,33,36,37,40,41,44,45,48,
%T A338062 49,52,53,56,57,60,61,64,65,68,69,72,73,76,77,80,81,84,85,88,89,92,93,
%U A338062 96,97,100,101,104,105,108,109,112,113,116,117,120,121,124,125,128,129,132,133,136,137
%N A338062 Numbers k such that the Enots Wolley sequence A336957(k) is odd.
%C A338062 a(n) = A042948(n) for n<=1065, but then the two sequences start to differ. - _R. J. Mathar_, Nov 06 2020
%H A338062 N. J. A. Sloane, <a href="/A338062/b338062.txt">Table of n, a(n) for n = 1..20000</a>
%t A338062 M = 1000;
%t A338062 A[1] = 1; A[2] = 2;
%t A338062 Clear[B]; B[_] = 0;
%t A338062 For[n = 3, True, n++, For[k = 3, k <= M, k++, If[B[k] == 0 && GCD[k, A[n-1]] > 1 && GCD[k, A[n-2]] == 1, If[Length[FactorInteger[k][[All, 1]] ~Complement~ FactorInteger[A[n-1]][[All, 1]]] > 0, A[n] = k; B[k] = 1; Break[]]]]; If[k > M, Break[]]];
%t A338062 Reap[For[k = 1, k <= M, k++, If[OddQ[A[k]], Sow[k]]]][[2, 1]] (* _Jean-François Alcover_, Oct 23 2020, after Maple code in A336957 *)
%Y A338062 Cf. A336957, A338063-A338069.
%K A338062 nonn
%O A338062 1,2
%A A338062 _N. J. A. Sloane_, Oct 18 2020