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 A140218 #4 Mar 30 2012 18:51:58 %S A140218 1,1,1,1,2,1,1,2,1,1,1,4,1,2,1,1,4,1,2,1,1,1,4,1,1,1,2,1,1,4,1,1,1,2, %T A140218 1,1,1,8,1,2,1,4,1,2,1,1,8,1,2,1,4,1,2,1,1,1,8,1,1,1,4,1,2,1,2,1,1,8, %U A140218 1,1,1,4,1,2,1,2,1,1,1,8,1,2,1,2,1,2,1,4,1,2,1,1,8,1,2,1,2,1,2,1,4,1,2,1,1 %N A140218 Denominators of the inverse triangle to that described in A133135. %C A140218 The inverse of the triangle of fractions starts %C A140218 1; %C A140218 -1, 1; %C A140218 1, -3/2, 1; %C A140218 -1, 3/2,-2, 1; %C A140218 1, -5/4, 2, -5/2, 1; %C A140218 -1, 5/4 -1, 5/2, -3, 1; %C A140218 1, -7/4, 1, 0, 3, -7/2, 1; %C A140218 -1, 7/4,-4, 0, 2, 7/2,-4, 1; %C A140218 1, 3/8, 4,-21/2, -2, 21/4, 4,-9/2, 1; %C A140218 -1, -3/8,13, 21/2,-26,-21/4,10, 9/2,-5, 1; %C A140218 to yield the triangle of denominators %C A140218 1; %C A140218 1,1; %C A140218 1,2,1; %C A140218 1,2,1,1; %C A140218 1,4,1,2,1; %C A140218 1,4,1,2,1,1; %C A140218 1,4,1,1,1,2,1; %C A140218 1,4,1,1,1,2,1,1; %C A140218 1,8,1,2,1,4,1,2,1; %C A140218 1,8,1,2,1,4,1,2,1,1; %C A140218 1,8,1,1,1,4,1,2,1,2,1; %C A140218 1,8,1,1,1,4,1,2,1,2,1,1; %C A140218 Number pairs show up if reading this along diagonals or columns. %Y A140218 Cf. A133135, A140216, A000079. %K A140218 nonn,frac,tabl %O A140218 0,5 %A A140218 _Paul Curtz_, Jun 22 2008 %E A140218 Extended by _R. J. Mathar_, Aug 02 2008