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 A259100 #14 Nov 07 2017 18:28:11 %S A259100 1,0,1,0,2,1,0,3,2,1,0,4,5,2,1,0,5,8,5,2,1,0,6,14,10,5,2,1,0,7,20,18, %T A259100 10,5,2,1,0,8,30,30,20,10,5,2,1 %N A259100 Triangle read by rows, arising in the enumeration of corners. %H A259100 G. Kreweras, <a href="http://dx.doi.org/10.1016/0012-365X(79)90163-8">Sur les extensions linéaires d'une famille particuliere d'ordres partiels</a>, Discrete Math., 27 (1979), 279-295. %H A259100 G. Kreweras, <a href="/A006330/a006330_1.pdf">Sur les extensions linéaires d'une famille particulière d'ordres partiels</a>, Discrete Math., 27 (1979), 279-295. (Annotated scanned copy) %F A259100 Kreweras gives a recurrence on page 281. %e A259100 Triangle begins: %e A259100 1; %e A259100 0, 1; %e A259100 0, 2, 1; %e A259100 0, 3, 2, 1; %e A259100 0, 4, 5, 2, 1; %e A259100 0, 5, 8, 5, 2, 1; %e A259100 0, 6, 14, 10, 5, 2, 1; %e A259100 0, 7, 20, 18, 10, 5, 2, 1; %e A259100 0, 8, 30, 30, 20, 10, 5, 2, 1; %e A259100 ... %Y A259100 Row sums = A006330. %K A259100 nonn,tabl,more %O A259100 0,5 %A A259100 _N. J. A. Sloane_, Jun 22 2015