A064473 Where the odd terms appear in A064413 (if it begins at 2).

4, 5, 9, 10, 13, 14, 19, 20, 21, 23, 24, 27, 28, 32, 33, 36, 37, 38, 42, 43, 49, 50, 52, 53, 56, 57, 60, 61, 66, 67, 68, 73, 74, 75, 77, 80, 81, 83, 84, 88, 89, 92, 95, 96, 99, 100, 106, 107, 108, 110, 111, 114, 115, 117, 118, 123, 124, 127, 128

Offset: 1

Author

N. J. A. Sloane, Oct 05 2001

Keywords

• nonn

Links

• J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, Exper. Math. 11 (2002), 437-446.
• Index entries for sequences related to EKG sequence

Crossrefs

Cf. A064413. See A064957 for better version.

Programs

Mathematica

ekg[s_] := Block[{m = s[[-1]], k = 3}, While[MemberQ[s, k] || GCD[m, k] == 1, k++]; Append[s, k]];
EKG = Nest[ekg, {1, 2}, 200] // Rest;
Position[EKG, ?OddQ] // Flatten (* _Jean-François Alcover, Feb 07 2019, after Robert G. Wilson v in A064413 *)