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 A239579 #7 Mar 21 2014 19:57:45
%S A239579 1,0,1,0,0,2,3,2,0,3,1,2,2,3,2,2,1,3,3,1,1,1,8,4,3,1,2,4,2,2,4,5,3,4,
%T A239579 5,3,6,4,6,3,5,5,6,3,3,10,5,10,4,3,6,4,4,7,6,5,3,3,6,5,6,3,5,9,3,6,5,
%U A239579 8,4,9,9,10,7,12,4,9,7,7,10,11
%N A239579 a(n) = |{0 < k <= n: prime(prime(prime(k*n))) - 2 is prime}|.
%C A239579 Conjecture: (i) a(n) > 0 for all n > 9.
%C A239579 (ii) If n > 0 is not equal to 5, then prime(prime(k*n)) + 2 is prime for some k = 1, ..., n.
%H A239579 Zhi-Wei Sun, <a href="/A239579/b239579.txt">Table of n, a(n) for n = 1..3000</a>
%H A239579 Zhi-Wei Sun, <a href="http://arxiv.org/abs/1402.6641">Problems on combinatorial properties of primes</a>, arXiv:1402.6641, 2014.
%e A239579 a(3) = 1 since prime(prime(prime(1*3))) - 2 = prime(prime(5)) - 2 = prime(11) - 2 = 31 - 2 = 29 is prime.
%t A239579 p[n_]:=PrimeQ[Prime[Prime[Prime[n]]]-2]
%t A239579 a[n_]:=Sum[If[p[k*n],1,0],{k,1,n}]
%t A239579 Table[a[n],{n,1,80}]
%Y A239579 Cf. A000040, A001359, A006512, A238573.
%K A239579 nonn
%O A239579 1,6
%A A239579 _Zhi-Wei Sun_, Mar 21 2014