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 A140216 #4 Mar 30 2012 18:51:58 %S A140216 1,-1,1,1,-3,1,-1,3,-2,1,1,-5,2,-5,1,-1,5,-1,5,-3,1,1,-7,1,0,3,-7,1, %T A140216 -1,7,-4,0,2,7,-4,1,1,3,4,-21,-2,21,4,-9,1,-1,-3,13,21,-26,-21,10,9, %U A140216 -5,1,1,-121,-13,66,26,-231,-10,33,5,-11,1,-1,121,-142,-66,229,231,-116,-33,25,11,-6 %N A140216 Numerators of the inverse triangle defined in A133135. %C A140216 Row sums 1, 0, -1, 1, -6, 6, -8, 8, 2, -2,.. build in pairs. %e A140216 The triangle starts %e A140216 1; %e A140216 -1, 1; %e A140216 1,-3, 1; %e A140216 -1, 3,-2, 1; %e A140216 1,-5, 2, -5, 1; %e A140216 -1, 5,-1, 5, -3, 1; %e A140216 1,-7, 1, 0, 3, -7, 1; %e A140216 -1, 7,-4, 0, 2, 7,-4, 1; %e A140216 1, 3, 4,-21, -2, 21, 4,-9, 1; %e A140216 -1,-3,13, 21,-26,-21,10, 9,-5,1; %e A140216 Pairs of numbers appear along adjacent diagonals. The first subdiagonal contains the sequence -A026741(n+2). %Y A140216 Cf. A133135, A140218. %K A140216 sign,frac,tabl %O A140216 0,5 %A A140216 _Paul Curtz_, Jun 22 2008 %E A140216 Edited by _R. J. Mathar_, Aug 06 2008