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 A249224 #9 Oct 27 2014 05:32:36
%S A249224 2,13,3,2,2,3,3,2,2,3,11,2,2,5,3,2,2,3,3,2,2,3,17,2,2,13,3,2,2,3,3,2,
%T A249224 2,3,5,2,2,7,3,2,2,3,3,2,2,3,29,2,2,5,3,2,2,3,3,2,2,3,5,2,2,31,3,2,2,
%U A249224 3,3,2,2,3,41,2,2,5,3,2,2,3,3,2,2,3,47,2,2,43,3,2,2,3,3,2,2,3,5,2,2,7,3,2
%N A249224 Lpf (n(n+11)/2): least prime dividing n(n+11)/2.
%C A249224 a(n) = 2 for n = {4,5,8,9} (mod 12) and a(n) = 3 for n = {3,6,7,10} (mod 12).
%H A249224 Zak Seidov, <a href="/A249224/b249224.txt">Table of n, a(n) for n = 1..10000</a>
%F A249224 a(n) = A020639(n(n+11)/2).
%t A249224 FactorInteger[#(11+#)/2][[1,1]]& /@ Range[100]
%o A249224 (PARI) a(n) = my(f=factor(n*(n+11)/2)); f[1,1]; \\ _Michel Marcus_, Oct 23 2014
%Y A249224 Cf. A056115, A020639.
%K A249224 nonn,easy
%O A249224 1,1
%A A249224 _Zak Seidov_, Oct 23 2014