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 A007888 #7 Feb 14 2018 21:10:57 %S A007888 1,1,3,2,3,4,1,-6,45,-86,173,-100,2641,-48311,717766,-15527527, %T A007888 395694683,-11210796201,356923346235,-12694851400717,501010779605741, %U A007888 -21827969798073020,1044997258445975691,-54740156237911040100 %N A007888 Euler characteristic of mapping class group Gamma_n. %D A007888 Harer, J., The cohomology of the moduli space of curves, Lecture Notes in Math., Vol. 1337, Springer-Verlag, NY, pp. 138-221 %H A007888 Sean A. Irvine, <a href="/A007888/b007888.txt">Table of n, a(n) for n = 1..37</a> %K A007888 sign %O A007888 1,3 %A A007888 _Mira Bernstein_ %E A007888 More terms from _Sean A. Irvine_, Feb 14 2018