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 A180501 #7 Oct 07 2019 11:40:29 %S A180501 1,1,1,1,1,1,1,3,9,46,2,16,265,6998,153528 %N A180501 Triangle read by row. T(n,m) gives the number of isomorphism classes of arrangements of n pseudolines and m double pseudolines in the projective plane. %D A180501 J. Ferté, V. Pilaud and M. Pocchiola, On the number of arrangements of five double pseudolines, Abstracts 18th Fall Workshop on Comput. Geom. (FWCG08), Troy, NY, October 2008. %H A180501 J. Ferté, V. Pilaud and M. Pocchiola, <a href="https://arxiv.org/abs/1009.1575">On the number of simple arrangements of five double pseudolines</a>, arXiv:1009.1575 [cs.CG], 2010; Discrete Comput. Geom. 45 (2011), 279-302. %Y A180501 See A180500 for isomorphism classes of simple arrangements of n pseudolines and m double pseudolines in the projective plane. %Y A180501 See A180502 for isomorphism classes of arrangements of n pseudolines and m double pseudolines in the Moebius strip. %Y A180501 First diagonal gives A063800. %K A180501 nonn,tabl,more %O A180501 0,8 %A A180501 _Vincent Pilaud_, Sep 08 2010