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%I #11 Jul 11 2015 10:19:03
%S 4,6,9,12,16,18,19,20,24,29,31,34,35,39,40,44,46,49,51,54,55,72,73,76,
%T 79,80,81,84,87,91,93,94,96,98,110,113,116,120,128,130,136,137,148,
%U 150,154,159,165,168,170,172,175,188,190,191,199,200,206,215,217,220,230
%N Numbers n such that n plus n-th semiprime is semiprime.
%C This is the semiprime analog of A064402.
%H Harvey P. Dale, <a href="/A100915/b100915.txt">Table of n, a(n) for n = 1..1000</a>
%H Eric Weisstein, World of Mathematics, <a href="http://mathworld.wolfram.com/Semiprime.html">Semiprime.</a>
%F a(n) = A100466(n) - A100916(n) = A100466(n) - A001358(A100915(n)).
%e a(3) = 9 because 9 + semiprime(9) = 9 + 25 = 34 is semiprime.
%t With[{c=Select[Range[1000],PrimeOmega[#]==2&]},Transpose[Select[Thread[ {c,Range[ Length[c]]}], PrimeOmega[Total[#]]==2&]][[2]]] (* _Harvey P. Dale_, Oct 25 2011 *)
%Y Cf. A001358, A064402, A100493, A100466, A100467, A100916.
%K easy,nonn
%O 1,1
%A _Ray Chandler_, Nov 26 2004
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