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%I #14 Oct 20 2019 22:36:34
%S 1,2,4,3,5,10,7,14,8,6,11,22,12,9,13,15,16,17,18,19,20,21,23,46,25,50,
%T 26,24,30,27,31,62,29,28,33,32,37,74,35,34,38,36,44,39,40,47,41,42,52,
%U 43,45,51,48,49,53,54,56,55,57,58,60,59,61,63,64,65,66,67,68,69,70,71
%N a(1) = 1; a(n+1) = gcd(n,a(n))-th smallest positive integer not already in the sequence.
%C Probably a permutation of the positive integers.
%C This is a permutation iff, infinitely often, gcd(n, a(n)) = 1. Through n = 1000, gcd(n, a(n)) = 1 612 times, which is consistent with the natural conjecture that this is true with density 6/Pi^2 ~ 0.6079.... - _Franklin T. Adams-Watters_, Nov 28 2006
%H Franklin T. Adams-Watters, <a href="/A100826/b100826.txt">Table of n, a(n) for n = 1..1000</a>
%t a[1] = 1; a[n_] := a[n] = Complement[ Range[250], Table[a[i], {i, n - 1}]][[GCD[n - 1, a[n - 1]]]]; Table[ a[n], {n, 60}] (* _Robert G. Wilson v_, Jan 10 2005 *)
%Y Cf. A125628.
%K nonn
%O 1,2
%A _Leroy Quet_, Jan 06 2005
%E More terms from _Robert G. Wilson v_, Jan 10 2005
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