%I A118966
%S A118966 1,3,2,7,9,11,4,15,5,19,6,23,25,27,8,31,33,35,10,39,41,43,12,47,13,51,
%T A118966 14,55,57,59,16,63,17,67,18,71,73,75,20,79,21,83,22,87,89,91,24,95,97,
%U A118966 99,26,103,105,107,28,111,29,115,30,119,121,123,32,127,129,131,34,135
%N A118966 If n doesn't occur among the first (n-1) terms of the sequence, then 
               a(n)= 2n-1. If n occurs among the first (n-1) terms of the sequence, 
               then a(n) = (n+1)/2.
%C A118966 Sequence is a permutation of the positive integers. It also is its own 
               inverse (i.e. a(a(n)) = n).
%H A118966 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%t A118966 f[s_] := Block[{n = Length@s}, Append[s, If[MemberQ[s, n], (n + 1)/2, 
               2n - 1]]]; Rest@Nest[f, {1}, 70] - Robert G. Wilson v (rgwv(at)rgwv.com), 
               May 16 2006
%Y A118966 Cf. A118967.
%Y A118966 Sequence in context: A026172 A026186 A026210 this_sequence A018891 A034423 
               A099329
%Y A118966 Adjacent sequences: A118963 A118964 A118965 this_sequence A118967 A118968 
               A118969
%K A118966 easy,nonn
%O A118966 1,2
%A A118966 Leroy Quet May 07 2006
%E A118966 More terms from Robert G. Wilson v (rgwv(at)rgwv.com), May 16 2006