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a(n+1) = if {a(k):1<=k<=n} is a permutation of [1:n] then 2*a(n) else a(n)-1.
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%I #7 Mar 30 2012 18:50:58

%S 1,2,4,3,6,5,10,9,8,7,14,13,12,11,22,21,20,19,18,17,16,15,30,29,28,27,

%T 26,25,24,23,46,45,44,43,42,41,40,39,38,37,36,35,34,33,32,31,62,61,60,

%U 59,58,57,56,55,54,53,52,51,50,49,48,47,94,93,92,91,90,89,88,87,86,85

%N a(n+1) = if {a(k):1<=k<=n} is a permutation of [1:n] then 2*a(n) else a(n)-1.

%C Self-inverse permutation of natural numbers;

%C a(A052955(n)) = A027383(n);

%C a(A052955(n)-1)=a(A052955(n))/2; a(A052955(n)+1)=a(A052955(n))-1.

%C Almost certainly A132666 is a duplicate of this entry. - _R. J. Mathar_, Jun 12 2008

%H R. Zumkeller, <a href="/A132340/b132340.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Aug 20 2007