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 A129884 #5 Mar 30 2013 04:51:09
%S A129884 1,1,4,4,16,17,72,79
%N A129884 Sequence a_{s_n} arising in enumeration of arrays of directed blocks (see Quaintance reference for precise definition), where a_n = A129878, s_n = A129873.
%D A129884 Jocelyn Quaintance, Combinatoric Enumeration of Two-Dimensional Proper Arrays, Discrete Math., 307 (2007), 1844-1864.
%F A129884 See Quaintance reference for generating functions that produce A129872-A129886.
%K A129884 nonn,more
%O A129884 1,3
%A A129884 _N. J. A. Sloane_, May 26 2007