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 A090163 #3 Mar 31 2012 10:29:03 %S A090163 1,1,1,1,1,2,1,1,18 %N A090163 Triangle T(j,k) read by rows, where T(j,K)=number of different configurations having the largest required number of moves S(j,k)=A090033(n) in optimal solutions of the j X k generalization of Sam Loyd's sliding block 15-puzzle, starting with the empty square in a corner. %C A090163 T(k,j)=T(j,k). Extension: a(10)=T(4,4)>=13, a(11)=T(5,1)=1, a(12)=T(5,2)=2. %H A090163 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/sbpnx2.txt">Solutions of small n*2 sliding block puzzles.</a> %e A090163 a(5)=T(3,2)=1 because the 3*2 sliding block puzzle has only one configuration requiring the maximum solution path length A090033(5)=21. %e A090163 A090034(21)=1, see link. %Y A090163 For references, links and cross-references see A087725 and A090033. %K A090163 hard,more,nonn,tabl %O A090163 1,6 %A A090163 _Hugo Pfoertner_, Nov 23 2003