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 A082663 #32 Jul 31 2021 19:18:32 %S A082663 15,35,77,91,143,187,209,221,247,299,323,391,437,493,527,551,589,667, %T A082663 703,713,851,899,943,989,1073,1147,1189,1247,1271,1333,1363,1457,1517, %U A082663 1537,1591,1643,1739,1763,1829,1891,1927,1961,2021,2173,2183,2257,2279 %N A082663 Odd semiprimes pq with p < q < 2p. %C A082663 Numbers k such that A082647(k) = A000005(k) - 1 = 3. %C A082663 A082647(p^2) = A000005(p^2) - 1 = 2, where p is odd prime. %C A082663 Numbers n such that A229964(n) = 2. - _Eric M. Schmidt_, Oct 05 2013 %H A082663 Amiram Eldar, <a href="/A082663/b082663.txt">Table of n, a(n) for n = 1..10000</a> (terms 1...1000 from Vincenzo Librandi) %t A082663 f[n_]:=Last/@FactorInteger[n]=={1,1}&&FactorInteger[n][[1,1]]>2&&Floor[FactorInteger[n][[2,1]]/FactorInteger[n][[1,1]]]==1;lst={};Do[If[f[n],AppendTo[lst,n]],{n,7!}];lst (* _Vladimir Joseph Stephan Orlovsky_, May 19 2010 *) %t A082663 pq2pQ[n_]:=Module[{fi=FactorInteger[n][[All,1]]},PrimeOmega[n]==2 && fi[[1]]< fi[[2]]< 2fi[[1]]]; Select[Range[1,2301,2],pq2pQ]//Quiet (* _Harvey P. Dale_, Jul 31 2021 *) %o A082663 (PARI) list(lim)=my(v=List()); forprime(p=3, sqrtint(lim\=1), forprime(q=p+1,min(lim\p,2*p), listput(v,p*q))); Set(v) \\ _Charles R Greathouse IV_, Mar 03 2021 %Y A082663 Cf. A000005, A056913, A046388, A082647, A229964. %K A082663 easy,nonn %O A082663 1,1 %A A082663 _Naohiro Nomoto_, May 18 2003 %E A082663 New name based on a Jan 23 2004 comment from _Vladeta Jovovic_ - _Charles R Greathouse IV_, Mar 03 2021