This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A115585 #17 Oct 31 2013 12:17:37 %S A115585 4,9,14,21,25,26,33,38,46,49,57,62,69,74,85,93,94,106,121,129,133,134, %T A115585 145,166,169,177,178,205,213,217,218,226,237,249,253,254,262,265,278, %U A115585 289,309,314,334,361,362,393,398,417,422,445,466,469,489,493,502,505 %N A115585 Semiprimes with a semiprime sum of factors. %H A115585 Zak Seidov, <a href="/A115585/b115585.txt">Table of n, a(n) for n = 1..1000</a> %e A115585 314 = 2*157 and 2 + 157 = 159 =3 * 53 (semiprime). %t A115585 fQ[n_] := Plus @@ Last /@ FactorInteger@n == 2; Select[ Range@513, fQ@# && fQ[ Plus @@ Flatten[ Table[First@#, {Last@#}] & /@ FactorInteger@# ]] &] (* _Robert G. Wilson v_ *) %t A115585 Select[Range[600],PrimeOmega[#]==PrimeOmega[Total[Flatten[Table[#[[1]],{#[[2]]}]&/@FactorInteger[#]]]]==2&] (* _Harvey P. Dale_, Jan 22 2013 *) %o A115585 (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 A115585 Cf. A001358, A068318. %K A115585 nonn %O A115585 1,1 %A A115585 _Zak Seidov_, Mar 09 2006 %E A115585 More terms from _Robert G. Wilson v_, Apr 12 2006