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 A228630 #6 Aug 28 2013 08:31:21
%S A228630 4,0,0,0,56,144,180,220,1716,5928,14560,26880,97680,344352,978588,
%T A228630 2346120,7444580,25763640,79547622,213434848,663024312,2288434800,
%U A228630 7496808800,21967834824,68476484916,235311849416,802176548700,2519791766160,8048777883936
%N A228630 Number of s in {1,...,n}^n having shortest run with the same value of length 4.
%H A228630 Alois P. Heinz, <a href="/A228630/b228630.txt">Table of n, a(n) for n = 4..180</a>
%e A228630 a(4) = 4: [1,1,1,1], [2,2,2,2], [3,3,3,3], [4,4,4,4].
%e A228630 a(8) = 2*C(8,2) = 56: [1,1,1,1,2,2,2,2], ..., [8,8,8,8,7,7,7,7].
%Y A228630 Column k=4 of A228617.
%K A228630 nonn
%O A228630 4,1
%A A228630 _Alois P. Heinz_, Aug 28 2013