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 A300438 #4 Mar 05 2018 15:21:56 %S A300438 1,4,9,19,40,83,173,360,749,1559,3244,6751,14049,29236,60841,126611, %T A300438 263480,548307,1141037,2374520,4941421,10283191,21399516,44532799, %U A300438 92673601,192855524,401336009,835187859,1738041800,3616898003,7526833453,15663483400,32596006509,67832908759,141161571724,293759912351 %N A300438 Expansion of (1+x)^3/(1-x-2*x^2-x^3+x^4). %C A300438 The number of N-color odd self-inverse compositions of (2*n+1). %H A300438 Y.-h. Guo, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL17/Guo/guo9.html">n-Color Odd Self-Inverse Compositions</a>, J. Int. Seq. 17 (2014) # 14.10.5, Table 1 and Corollary 11. %H A300438 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1,2,1,-1). %Y A300438 Row sums of A300437. %Y A300438 Cf. A119749. %K A300438 nonn,easy %O A300438 0,2 %A A300438 _R. J. Mathar_, Mar 05 2018