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A064420 Numbers n such that A064413(n+1) = n. Probably complete. 0
16, 26, 49, 77, 289 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If A064413 begins at 2 these are the n such that A064413(n) = n.

LINKS

Table of n, a(n) for n=1..5.

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 = 500;

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];

For[n = 1, n <= nmax, n++, If[EKG[[n+1]] == n, Print[n]]] (* Jean-Fran├žois Alcover, Feb 13 2019, after Robert G. Wilson v in A064413 *)

CROSSREFS

Sequence in context: A171144 A204543 A155549 * A038353 A043126 A043906

Adjacent sequences:  A064417 A064418 A064419 * A064421 A064422 A064423

KEYWORD

nonn,more

AUTHOR

Jonathan Ayres (Jonathan.ayres(AT)btinternet.com), Sep 30 2001

EXTENSIONS

No others below 10000 - Vladeta Jovovic, Oct 03 2001

No others below 10954981 - Eric M. Rains (rains(AT)caltech.edu), Oct 05, 2001.

STATUS

approved

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Last modified August 4 10:01 EDT 2021. Contains 346446 sequences. (Running on oeis4.)