%I A118967
%S A118967 1,4,6,2,10,3,14,16,18,5,22,24,26,7,30,8,34,9,38,40,42,11,46,12,50,13,
%T A118967 54,56,58,15,62,64,66,17,70,72,74,19,78,20,82,21,86,88,90,23,94,96,98,
%U A118967 25,102,104,106,27,110,28,114,29,118,120,122,31,126,32,130,33,134,136
%N A118967 If n doesn't occur among the first (n-1) terms of the sequence, then 
               a(n) = 2n. If n occurs among the first (n-1) terms of the sequence, 
               then a(n) = n/2.
%C A118967 Sequence is a permutation of the positive integers. It also is its own 
               inverse (i.e. a(a(n)) = n).
%H A118967 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%t A118967 f[s_] := Block[{n = Length@s}, Append[s, If[ MemberQ[s, n], n/2, 2n]]]; 
               Drop[ Nest[f, {1}, 70], {2}] - Robert G. Wilson v (rgwv(AT)rgwv.com), 
               May 16 2006
%Y A118967 Cf. A118966.
%Y A118967 Sequence in context: A095196 A074828 A159193 this_sequence A059030 A066984 
               A085595
%Y A118967 Adjacent sequences: A118964 A118965 A118966 this_sequence A118968 A118969 
               A118970
%K A118967 easy,nonn
%O A118967 1,2
%A A118967 Leroy Quet May 07 2006
%E A118967 More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), May 16 2006