

A064470


The even subsequence of A064413, divided by 2.


0



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
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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), 437446.
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 (* JeanFrançois 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



