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 A240436 #21 Aug 26 2014 09:30:17
%S A240436 4,21,115,329,2171,6821,24331,50579,79421,103729,226859,357769,704791,
%T A240436 1092521,1224829,2048129,2247829,2685341,5177371,6967489,9393509,
%U A240436 11089121,12648871,13651441,16974079,25153171,30663671,38272079,46267561,74617619,86937421,90517951
%N A240436 Semiprimes of the form n^3 - 2*n.
%C A240436 Intersection of A001358 and A242135.
%C A240436 Since n^3 - 2*n = n * (n^2 - 2), it follows that n and (n^2 - 2) both should be prime.
%H A240436 K. D. Bajpai, <a href="/A240436/b240436.txt">Table of n, a(n) for n = 1..10545</a>
%F A240436 a(n) = A062326(n) * (A062326(n)^2 - 2). - _Michel Marcus_, Aug 26 2014
%e A240436 a(2) = 21: 3^3 - 2*3 = 27 - 6 = 21 = 3 * 7, which is semiprime.
%e A240436 a(3) = 115: 5^3 - 2*5 = 125 - 10 = 115 = 5 * 23, which is semiprime.
%p A240436 select(k -> numtheory:-bigomega(k)=2, [seq((n^3-2*n), n=1..500)]);
%t A240436 Select[Table[n^3 - 2*n, {n, 1000}], PrimeOmega[#] == 2 &]
%o A240436 (PARI) forprime(p=1,10^3,q=p^2-2;if(isprime(q),print1(p*q,", "))) \\ _Derek Orr_, Aug 17 2014
%Y A240436 Cf. A001358, A062326, A242135, A062326.
%K A240436 nonn,easy
%O A240436 1,1
%A A240436 _K. D. Bajpai_, Aug 17 2014