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 A242936 #5 May 29 2014 10:10:21
%S A242936 2,5,9,11,13,16,17,22,23,27,28,30,31,33,37,38,41,42,44,45,47,53,56,58,
%T A242936 61,64,65,67,68,70,73,74,75,76,80,81,84,85,88,90,92,93,96,99,102,105,
%U A242936 106,107,108,109,110,112,114,116,117,119,122,123,124,125,126,129
%N A242936 Numbers n such that n*prime(n) + (n+1)*(prime(n+1)) is semiprime.
%H A242936 K. D. Bajpai, <a href="/A242936/b242936.txt">Table of n, a(n) for n = 1..10000</a>
%e A242936 a(2) = 5: 5*prime(5) + (5+1)*prime(5+1) = 133 = 7 * 19 which is semiprime.
%e A242936 a(3) = 9: 9*prime(9) + (9+1)*prime(9+1) = 497 = 7 * 71 which is semiprime.
%p A242936 with(numtheory): A242936:= proc() if bigomega(n*ithprime(n) + (n+1)*ithprime(n+1) = 2 then return (n) : fi; end: seq(A242936 (), n=1..500);
%t A242936 c = 0; Do[If[PrimeOmega[n*Prime[n] + (n+1)*Prime[n+1]]==2, c++; Print[c," ",n]], {n,1,35000}];
%Y A242936 Cf. A000040, A001358, A105455.
%K A242936 nonn
%O A242936 1,1
%A A242936 _K. D. Bajpai_, May 27 2014