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 A120476 #11 Mar 12 2014 16:36:53
%S A120476 1,3,-2,6,-5,-9,10,-9,-21,-20,15,-14,-36,-45,-35,21,-20,-54,-75,-77,
%T A120476 -54,28,-27,-75,-110,-126,-117,-77,36,-35,-99,-150,-182,-189,-165,
%U A120476 -104,45,-44,-126,-195,-245,-270,-264,-221,-135,55,-54,-156,-245,-315,-360,-374,-351,-285,-170
%N A120476 Triangle read by rows: a(n,m)=(2*n-1)*(n-m)*(n+m+1)/2, where n is the column and m the row index.
%C A120476 Triangular array based on recurrence in Laplace function in J. W. S. Rayleigh.
%D A120476 J. W. S. Rayleigh, The Theory of Sound, volume 2, page 237,Dover, New York,1945
%F A120476 a(n,m) = (2n-1)*[A000217(n)-A000217(m)] = (1-2n)*A049777(n,m) . - _R. J. Mathar_, Dec 05 2007
%F A120476 Row sums: sum_{n=0..m-1} a(n,m) = -m(m+1)(3m^2-5m-4)/12. [From _R. J. Mathar_, Jan 15 2009]
%e A120476 1,
%e A120476 3, -2,
%e A120476 6, -5, -9,
%e A120476 10, -9, -21,-20,
%e A120476 15, -14,-36,-45, -35
%t A120476 a = Table[Table[(m + 1)*(2*n - 1)*(n - m)*(n + m + 1)/(2*(m + 1)), {n, 0, m - 1}], {m, 1, 10}] Flatten[a]
%Y A120476 Cf. A006472.
%K A120476 sign,tabl
%O A120476 0,2
%A A120476 _Roger L. Bagula_, Jul 19 2006
%E A120476 Edited by _N. J. A. Sloane_, Oct 01 2006