%I #10 Jan 11 2019 09:57:52
%S 0,0,0,1,2,2,2,2,3,4,4,4,5,6,6,6,6,6,7,8,9,9,10,11,11,11,12,13,13,13,
%T 13,14,15,15,15,16,17,18,18,18,18,19,20,20,20,20,20,20,21,22,22,23,24,
%U 24,24,25,26,26,26,27,28,28,28,28,28,29,30,31,31,31
%N Number of odd terms among first n terms of A064413 (if it begins at 2).
%H J. C. Lagarias, E. M. Rains and N. J. A. Sloane, <a href="https://arxiv.org/abs/math/0204011">The EKG sequence</a>, arXiv:math/0204011 [math.NT], 2002; Exper. Math. 11 (2002), 437-446.
%H <a href="/index/Ed#EKG">Index entries for sequences related to EKG sequence</a>
%t ekg[s_] := Block[{m = s[[-1]], k = 3}, While[MemberQ[s, k] || GCD[m, k] == 1, k++]; Append[s, k]];
%t EKG = Nest[ekg, {1, 2}, 71] ;
%t a[n_] := Count[EKG[[2 ;; n]], _?OddQ];
%t Table[a[n], {n, 2, 71}] (* _Jean-François Alcover_, Jan 11 2019, after _Robert G. Wilson v_ in A064413 *)
%Y See A064952 for better version.
%K nonn
%O 2,5
%A _N. J. A. Sloane_, Oct 05 2001