%I A099257
%S A099257 1,3,2,4,9,5,6,7,8,10,21,11,12,13,14,15,16,17,18,19,20,22,45,23,24,25,
%T A099257 26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,46,93,47,48,
%U A099257 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71
%N A099257 a(1)=1, a(n+1) = if a(n)=n then 2*n+1 else smallest number not occurring 
               earlier.
%C A099257 Permutation of the natural numbers with inverse A099258;
%C A099257 a(A033484(n)) = A033484(n);
%C A099257 a(A033484(n) + 1) = 2*A033484(n) + 1 = A068156(n).
%H A099257 <a href="Sindx_Per.html#IntegerPermutation">Index entries for sequences 
               that are permutations of the natural numbers</a>
%F A099257 a(n) = if n = 3*2^k - 2 then n else (if n = 3*2^k - 1 then 2*n + 1 else 
               n - 1).
%Y A099257 Sequence in context: A075087 A084657 A019916 this_sequence A083762 A083164 
               A094962
%Y A099257 Adjacent sequences: A099254 A099255 A099256 this_sequence A099258 A099259 
               A099260
%K A099257 nonn
%O A099257 1,2
%A A099257 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 09 2004