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 A280389 #27 Jun 18 2017 16:55:59
%S A280389 15,21,25,35,39,49,55,57,65,77,85,91,93,95,115,119,121,129,133,143,
%T A280389 145,155,161,169,183,185,187,203,205,209,215,217,219,221,235,247,253,
%U A280389 259,265,287,289,295,299,301,305,309,319,323,327,329,335,341,355,361,365,371,377,391,395,403
%N A280389 Odd semiprimes that can be represented as 2p+3q, where p and q are primes.
%H A280389 Robert Israel, <a href="/A280389/b280389.txt">Table of n, a(n) for n = 1..10000</a>
%p A280389 N:= 10^3: # to get all terms <= N
%p A280389 Primes:= select(isprime, [2, seq(i, i=3..N/2, 2)]):
%p A280389 Cands:= select(t -> t::odd and t <= N, {seq(seq(2*p+3*q, p=Primes), q=Primes)}):
%p A280389 sort(convert(select(numtheory:-bigomega=2, Cands), list)); # _Robert Israel_, Jan 09 2017
%Y A280389 Cf. A046315 (odd semiprimes).
%Y A280389 Cf. A280405 (odd semiprimes which can NOT be represented as 2p+3q, where p and q are prime).
%K A280389 nonn
%O A280389 1,1
%A A280389 _Randy L. Ekl_, Jan 02 2017