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%I #17 Oct 31 2013 12:17:37
%S 4,9,14,21,25,26,33,38,46,49,57,62,69,74,85,93,94,106,121,129,133,134,
%T 145,166,169,177,178,205,213,217,218,226,237,249,253,254,262,265,278,
%U 289,309,314,334,361,362,393,398,417,422,445,466,469,489,493,502,505
%N Semiprimes with a semiprime sum of factors.
%H Zak Seidov, <a href="/A115585/b115585.txt">Table of n, a(n) for n = 1..1000</a>
%e 314 = 2*157 and 2 + 157 = 159 =3 * 53 (semiprime).
%t fQ[n_] := Plus @@ Last /@ FactorInteger@n == 2; Select[ Range@513, fQ@# && fQ[ Plus @@ Flatten[ Table[First@#, {Last@#}] & /@ FactorInteger@# ]] &] (* _Robert G. Wilson v_ *)
%t Select[Range[600],PrimeOmega[#]==PrimeOmega[Total[Flatten[Table[#[[1]],{#[[2]]}]&/@FactorInteger[#]]]]==2&] (* _Harvey P. Dale_, Jan 22 2013 *)
%o (PARI) list(lim)=my(v=List()); forprime(p=2, sqrt(lim), forprime(q=p, lim\p, if(bigomega(p+q)==2, listput(v, p*q)))); vecsort(Vec(v)) \\ _Charles R Greathouse IV_, Sep 09 2012
%Y Cf. A001358, A068318.
%K nonn
%O 1,1
%A _Zak Seidov_, Mar 09 2006
%E More terms from _Robert G. Wilson v_, Apr 12 2006
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