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 A242838 #5 May 24 2014 18:22:47
%S A242838 6,0,18,0,56,0,146,0,312,120,1037,1440,4658,9624,23906,52524,117032,
%T A242838 255732,542186,1150920,2370395,4902948,9912558,20084700,40045005,
%U A242838 79902108,157676536,310969848,608833717,1190681692,2317419418,4505327884,8732462296,16911676140
%N A242838 Number of compositions of n with difference -3 between the number of odd parts and the number of even parts, both counted without multiplicity.
%H A242838 Alois P. Heinz, <a href="/A242838/b242838.txt">Table of n, a(n) for n = 12..500</a>
%e A242838 a(12) = 6 = 3!: all permutations of {2,4,6}.
%Y A242838 Column k=-3 of A242626.
%K A242838 nonn
%O A242838 12,1
%A A242838 _Alois P. Heinz_, May 23 2014