%I #4 Mar 30 2012 17:26:04
%S 1,4,2,9,3,8,10,7,5,11,6,15,12,14,20,16,19,13,17,21,18,26,23,25,31,22,
%T 27,32,40,30,35,28,24,34,29,39,37,41,44,33,45,36,50,42,38,65,43,46,51,
%U 47,57,52,48,54,63,55,62,58,56,49,53,60,66,64,67,59,74,68,73,71,61,70
%N Position of 2n in A073662.
%C It is not clear that each even number will appear in A073662, though I've checked it up to 20000.
%F a(n) = position of (2n) in A073662: A073662(a(n)) = 2n.
%e a(1)=4 because 2*1=2 appears at 4th position in A073662, a(14)=14 because 2*14=28 appears at 14th position in A073662,
%Y Cf. A073662, A073664, A076023.
%K easy,nonn
%O 1,2
%A _Zak Seidov_, Sep 30 2002