A064423 Position of n-th prime in A064413 (if it begins at 2).

1, 4, 9, 13, 19, 27, 32, 36, 42, 56, 60, 66, 73, 80, 88, 99, 106, 114, 127, 133, 137, 150, 159, 166, 181, 188, 196, 202, 206, 215, 235, 252, 258, 263, 278, 286, 296, 304, 313, 327, 335, 343, 362, 370, 376, 380, 400, 419, 429, 437, 443, 457, 461, 473, 486, 500

Offset

1,2

Comments

It can be shown that this sequence is monotonic.

Links

Michael De Vlieger, Table of n, a(n) for n = 1..65536 (first 1000 terms from T. D. Noe)

J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, arXiv:math/0204011 [math.NT], 2002.

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

terms = 100;
ekg[s_] := Block[{m = s[[-1]], k = 3}, While[MemberQ[s, k] || GCD[m, k] == 1, k++]; Append[s, k]];
EKG = Nest[ekg, {2, 4}, 12 terms];
a[n_] := FirstPosition[EKG, Prime[n]][[1]];
Array[a, terms] (* Jean-François Alcover, Sep 02 2018, after Robert G. Wilson v in A064413 *)

Crossrefs

Cf. A064413, A064425. See A064955 for better version.

Sequence in context: A312980 A035104 A141224 * A312981 A312982 A312983

Adjacent sequences: A064420 A064421 A064422 * A064424 A064425 A064426

Keyword

nonn,nice

Author

N. J. A. Sloane, Sep 30 2001

Extensions

More terms from Vladeta Jovovic, Oct 01 2001

Status

approved