A064952 Number of odd terms among first n terms of A064413.

1, 1, 1, 1, 2, 3, 3, 3, 3, 4, 5, 5, 5, 6, 7, 7, 7, 7, 7, 8, 9, 10, 10, 11, 12, 12, 12, 13, 14, 14, 14, 14, 15, 16, 16, 16, 17, 18, 19, 19, 19, 19, 20, 21, 21, 21, 21, 21, 21, 22, 23, 23, 24, 25, 25, 25, 26, 27, 27, 27, 28, 29, 29, 29, 29, 29, 30, 31, 32, 32, 32

Offset

1,5

Links

Table of n, a(n) for n=1..71.

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

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}, 100];
Boole[OddQ[#]]& /@ EKG // Accumulate (* Jean-François Alcover, Sep 10 2018, after Robert G. Wilson v *)

Crossrefs

See A064475 for another version.

Sequence in context: A316355 A055768 A349909 * A255070 A176001 A194272

Adjacent sequences: A064949 A064950 A064951 * A064953 A064954 A064955

Keyword

nonn

Author

N. J. A. Sloane, Oct 30 2001

Status

approved