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 A242937 #5 May 29 2014 10:10:38
%S A242937 2,4,7,8,9,11,14,16,18,19,26,32,36,38,42,44,48,50,53,71,74,78,79,82,
%T A242937 86,94,95,98,104,108,111,114,118,122,124,126,136,141,146,154,162,166,
%U A242937 172,174,178,180,184,186,189,190,197,200,203,206,216,219,221,223,224
%N A242937 Numbers n such that n*prime(n) + (n+1)*(prime(n+1)) + (n+2)*(prime(n+2)) is semiprime.
%H A242937 K. D. Bajpai, <a href="/A242937/b242937.txt">Table of n, a(n) for n = 1..10000</a>
%e A242937 a(2) = 4: 4*prime(4) + (4+1)*prime(4+1) + (4+2)*prime(4+2) = 161 = 7 * 23 is semiprime.
%e A242937 a(5) = 9: 9*prime(9) + (9+1)*prime(9+1) + (9+2)*prime(9+2) = 838 = 2 * 419 is semiprime.
%p A242937 with(numtheory):A242937:= proc() if bigomega(ithprime(n)*n + ithprime(n+1)*(n+1) + ithprime(n+2)*(n+2)) = 2 then return (n) : fi; end: seq(A242937 (), n=1..500);
%t A242937 c = 0; Do[If[PrimeOmega[n*Prime[n] + (n+1)*Prime[n+1] + (n+2)*Prime[n+2]]==2, c++; Print[c," ",n]], {n,1,85000}];
%Y A242937 Cf. A000040, A001358, A105455.
%K A242937 nonn
%O A242937 1,1
%A A242937 _K. D. Bajpai_, May 27 2014