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 A174190 #5 Mar 30 2012 18:52:05 %S A174190 0,0,-3,0,-5,-8,0,-7,-3,-15,0,-9,-16,-21,-24,0,-11,-5,-1,-2,-35,0,-13, %T A174190 -24,-33,-40,-45,-48,0,-15,-7,-39,-3,-55,-15,-63,0,-17,-32,-5,-56,-65, %U A174190 -8,-77,-80,0,-19,-9,-51,-4,-3,-21,-91,-6,-99,0,-21,-40,-57,-72,-85,-96 %N A174190 Triangle T(n,m) = numerator of 1/n^2-1/(n-m)^2, read by rows. %C A174190 The triangle contains the initial values of the array described in A172370. %C A174190 Ignoring details of column indexing, these are the negated values of A061035. %e A174190 The triangle starts in column n=1, rows 0<=m<n as %e A174190 0; %e A174190 0,-3; %e A174190 0,-5,-8; %e A174190 0,-7,-3,-15; %e A174190 0,-9,-16,-21,-24; %K A174190 sign,easy,tabl %O A174190 1,3 %A A174190 _Paul Curtz_, Mar 11 2010 %E A174190 Comments compactified with reference to A172370, formula and example added - _R. J. Mathar_, Nov 23 2010