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 A242842 #6 May 24 2014 18:33:17 %S A242842 2,3,6,11,20,25,41,85,148,355,751,1701,3756,8255,17513,37038,76349, %T A242842 156618,317591,639142,1279302,2546711,5057675,10010975,19788607, %U A242842 39058684,77055159,151930328,299600229,590849561,1165782514,2301229945,4545782370,8985884632 %N A242842 Number of compositions of n with difference 2 between the number of odd parts and the number of even parts, both counted without multiplicity. %H A242842 Alois P. Heinz, <a href="/A242842/b242842.txt">Table of n, a(n) for n = 4..500</a> %e A242842 a(4) = 2: [1,3], [3,1]. %e A242842 a(5) = 3: [1,1,3], [1,3,1], [3,1,1]. %e A242842 a(6) = 6: [1,1,1,3], [1,1,3,1], [1,3,1,1], [3,1,1,1], [1,5], [5,1]. %Y A242842 Column k=2 of A242626. %K A242842 nonn %O A242842 4,1 %A A242842 _Alois P. Heinz_, May 23 2014