A064470 The even subsequence of A064413, divided by 2.

1, 2, 3, 6, 4, 5, 9, 7, 12, 8, 10, 11, 15, 14, 13, 18, 16, 17, 21, 19, 20, 22, 23, 24, 25, 26, 27, 28, 30, 35, 29, 33, 31, 36, 32, 34, 37, 39, 38, 40, 41, 42, 44, 43, 45, 50, 46, 47, 48, 49, 52, 51, 54, 53, 57, 55, 56, 58, 59, 60, 65, 61, 63, 70, 62, 64

Offset

1,2

Links

Table of n, a(n) for n=1..66.

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

Mathematica

nmax = 120;
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}, nmax];
Select[EKG, EvenQ]/2 (* Jean-François Alcover, Feb 13 2019, after Robert G. Wilson v in A064413 *)

Crossrefs

Cf. A064413.

Sequence in context: A054076 A194873 A194901 * A194052 A178484 A222758

Adjacent sequences: A064467 A064468 A064469 * A064471 A064472 A064473

Keyword

nonn

Author

N. J. A. Sloane, Oct 05 2001

Status

approved