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 A229967 #11 Nov 08 2015 03:56:13
%S A229967 18,26,28,39,65,115,119,133,319,341,377,403,481,517,629,697,731,779,
%T A229967 799,817,893,1007,1207,1219,1357,1403,1541,1769,1943,2059,2077,2117,
%U A229967 2201,2263,2291,2407,2449,2573,2759,2923,3071,3293,3589,3649,3737,3811,3827,3959
%N A229967 Numbers n such that A229964(n) = 4.
%C A229967 Equals {18, 26, 28, 39} UNION {pq | p, q prime, p >= 5 and (2p+3 <= q <= 3p-2 or (p == 2 (mod 3) and q = 4p+3))}.
%H A229967 Eric M. Schmidt, <a href="/A229967/b229967.txt">Table of n, a(n) for n = 1..1000</a>
%H A229967 Rosemary Sullivan and Neil Watling, <a href="http://www.emis.de/journals/INTEGERS/papers/n65/n65.Abstract.html">Independent Divisibility Pairs on the Set of Integers from 1 to N</a>, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 13, Paper A65, 2013.
%o A229967 (Sage) sum(([p * q for q in prime_range(2*p+3, 3*p-1)] for p in prime_range(5, 10000)), []) + [p * (4*p + 3) for p in prime_range(5, 10000) if (4*p+3).is_prime() and p%3==2] + [18, 26, 28, 39]
%Y A229967 Cf. A166684, A082663, A229965, A229966.
%K A229967 nonn
%O A229967 1,1
%A A229967 _Eric M. Schmidt_, Oct 04 2013