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%I #2 Mar 30 2012 18:52:52
%S 1,5,1,5,17,21,17,21,1,5,1,5,17,21,17,21,65,69,65,69,81,85,81,85,65,
%T 69,65,69
%N a(n) is in A145818 such that (4n-1-a(n))/2 is in A145818 as well
%C Note that a(4n)=a(4n-2), a(4n-1)=a(4n-3).
%Y A145818 A145812 A145819 A145822
%K nonn
%O 1,2
%A _Vladimir Shevelev_, Oct 20 2008