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%I #9 Sep 11 2013 17:24:49
%S 4,9,15,21,25,35,39,49,55,65,69,77,85,91,93,111,123,133,141,155,161,
%T 169,183,209,215,235,247,249,265,291,309,323,327,339,341,355,361,365,
%U 377,391,393,411,437,445,451,453,505,511,515,529,551,553,565,581,583,611
%N Semiprimes of the form prime(n) + prime(n+2) - prime(n+1).
%H Harvey P. Dale, <a href="/A104243/b104243.txt">Table of n, a(n) for n = 1..10000</a>
%t Union[Select[First[#]+Last[#]-#[[2]]&/@Partition[Prime[Range[200]],3,1], PrimeOmega[ #]==2&]] (* _Harvey P. Dale_, Sep 11 2013 *)
%o (PARI) lista(nn) = {sps = Set(); for (n=1, nn, if (bigomega(sp=prime(n) + prime(n+2) - prime(n+1))==2, sps = Set(concat(sps, sp)));); print(sps);} \\ _Michel Marcus_, Jun 03 2013
%K nonn
%O 1,1
%A _Giovanni Teofilatto_, Apr 03 2005
%E Corrected and extended by _Rick L. Shepherd_, May 18 2005
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