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%I #7 Nov 01 2019 19:45:47
%S 2,3,9,5,7,15,21,11,25,13,33,17,35,19,39,23,49,51,55,57,29,31,65,69,
%T 37,77,41,85,43,87,91,93,47,95,53,111,115,59,119,121,61,123,129,133,
%U 67,141,71,143,145,73,155,79,159,161,83,169,177,89,183,185,187,97,201,101,203
%N a(n)=n-th semiprime if n-th semiprime odd and n-th semiprime/2 if n-th semiprime even.
%H Harvey P. Dale, <a href="/A176570/b176570.txt">Table of n, a(n) for n = 1..1000</a>
%t If[EvenQ[#],#/2,#]&/@Select[Range[300],PrimeOmega[#]==2&] (* _Harvey P. Dale_, Nov 01 2019 *)
%Y Cf. A001358.
%K nonn
%O 1,1
%A _Juri-Stepan Gerasimov_, Apr 20 2010
%E Entries checked by _R. J. Mathar_, Apr 27 2010