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 A112101 #4 Mar 30 2012 16:50:20
%S A112101 1,3,10,58,722,19826,1161882,141436842,35192653666,17733070720738,
%T A112101 17997787816364330,36678689328450847514,149831453090755680149490,
%U A112101 1225618861520566592060441682,20064594684596858150355969600442,657195622713393693107201875915723402
%N A112101 Number of interval orders of magnitude n having no duplicate holdings (NODH).
%D A112101 W. T. Trotter, Combinatorics and Partially Ordered Sets, Johns Hopkins, 1992; see p. 195.
%F A112101 a(n) = Sum_{k=0..n} binomial(n, k)*A111491(k).
%K A112101 nonn
%O A112101 0,2
%A A112101 _N. J. A. Sloane_, Nov 28 2005