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 A048080 #4 Mar 30 2012 18:56:54
%S A048080 0,0,0,0,0,0,0,3,18,24,84,224,280,630,1270,1527,2937,5742,6930,15015,
%T A048080 35035,44044,108164,260064,328944,767244,1720944,2152710,4738410,
%U A048080 10329750,12890614,28583709,64071194,80628669,184657869
%N A048080 Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n+2)/3.
%K A048080 nonn
%O A048080 1,8
%A A048080 _Clark Kimberling_