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 A138476 #15 May 15 2016 16:50:20 %S A138476 1,0,2,2,0,4,0,2,0,8,-2,0,0,16,0,6,0,-8,0,32,2,0,-12,0,-32,64,0,10,0, %T A138476 -16,0,-96,0,128,-2,0,32,0,0,0,-256,0,256,0,-14,0,80,0,96,0,-640,0,512 %N A138476 Triangle read by rows: expansion of (1+3*t^2)/(1-t*(2*x-t)). %C A138476 See A135929 and A138034 for further information. %D A138476 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972; see Chapter 22. %F A138476 G.f.: (1+3*t^2)/(1-t*(2*x-t)). %K A138476 tabf,sign %O A138476 1,3 %A A138476 A. Bannour (managing_office069(AT)yahoo.fr), Mar 19 2008 %E A138476 New name from _Joerg Arndt_, May 15 2016