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 A243436 #21 Sep 21 2016 11:18:49
%S A243436 8,13,15,18,19,23,24,26,28,30,33,34,35,38,41,44,50,52,58,59,62,64,68,
%T A243436 70,72,73,74,75,76,78,79,80,82,83,88,89,91,92,96,98,99,100,105,106,
%U A243436 107,108,109,110,111,112,113,114,117,119,120,122,123,124,125,128,130
%N A243436 Numbers n such that n^2-n-1 is semiprime.
%H A243436 K. D. Bajpai, <a href="/A243436/b243436.txt">Table of n, a(n) for n = 1..10000</a>
%e A243436 13 is in the sequence because 13^2 - 13 - 1 = 155 = 5 * 31 is semiprime.
%e A243436 18 is in the sequence because 18^2 - 18 - 1 = 305 = 5 * 61 is semiprime.
%p A243436 with(numtheory):A243436 := proc() if bigomega(n^2-n-1)=2 then RETURN (n); fi; end: seq(A243436 (), n=1..200);
%t A243436 c = 0; Do[If[PrimeOmega[n^2-n-1] == 2, c++; Print[c," ",n]], {n,1,30000}];
%t A243436 Select[Range[200],PrimeOmega[#^2-#-1]==2&] (* _Harvey P. Dale_, Sep 21 2016 *)
%Y A243436 Cf. A001358, A165900.
%K A243436 nonn
%O A243436 1,1
%A A243436 _K. D. Bajpai_, Jun 06 2014