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 A112311 #3 Mar 30 2012 16:50:20 %S A112311 1,2,9,216,174960,146932807680,125937291507579224064000, %T A112311 108755666689817047890109782510255885778944000000, %U A112311 93143885917529328515023382841413836868525118214478405334515136630707122998865821696000000000000 %N A112311 a(1)=1, a(2)=2, a(3)=9; a(n) = n*(n - 2)*a(n - 1)^2/(n - 1). %C A112311 Lower bound to number of perfect Morse matchings of n-simplex. %D A112311 M. K. Chari and M. Joswig, Complexes of discrete Morse functions, Disc. Math. 302 (2005), 39-51. %Y A112311 Cf. A005271. %K A112311 nonn %O A112311 1,2 %A A112311 _N. J. A. Sloane_, Dec 01 2005