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%I #17 Oct 16 2023 12:04:34
%S 4,6,9,15,21,26,34,39,69,86,93,111,129,134,205,217,254,274,309,334,
%T 381,386,393,446,453,473,489,501,515,566,667,687,723,771,803,879,933,
%U 939,974,1003,1011,1126,1167,1207,1226,1234,1243,1286,1294,1299,1313,1465
%N Numbers which are both interprime and semiprime.
%C Ratio of the number of odd terms to the number of even terms increases with increasing n. - _Zak Seidov_, May 22 2015
%H Harvey P. Dale, <a href="/A078443/b078443.txt">Table of n, a(n) for n = 1..1000</a>
%e a[8]=39 because 39=(37+41)/2 and 39=3*13
%t Select[Mean/@Partition[Prime[Range[250]],2,1],PrimeOmega[#]==2&] (* _Harvey P. Dale_, Oct 08 2013 *)
%o (PARI) lista(nn) = {prevp = 2; forprime (p=3, nn, n = p + prevp; if (n % 2 == 0, if (bigomega(n/2) == 2, print1(n/2, ", "););); prevp = p;);} \\ _Michel Marcus_, Jun 09 2013
%Y Intersection of A001358 and A024675. - _Zak Seidov_, May 22 2015
%K nonn
%O 1,1
%A _Lior Manor_, Dec 31 2002