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 A135552 #17 Jan 08 2018 01:36:22
%S A135552 1,4,-1,11,-6,1,26,-22,8,-1,57,-64,37,-10,1,120,-163,130,-56,12,-1,
%T A135552 247,-382,386,-232,79,-14,1,502,-848,1024,-794,378,-106,16,-1,1013,
%U A135552 -1816,2510,-2380,1471,-576,137,-18,1,2036,-3797,5812,-6476,4944,-2517,834,-172,20,-1,4083,-7814,12911,-16384,14893,-9402,4048,-1160,211,-22,1
%N A135552 Riordan array (1/((1-2x)(1-x)^2), -x/(1-x)^2).
%C A135552 Row sums are A024495. First column is essentially A000295, second column is essentially -A002663. - _Ralf Stephan_, Jan 03 2014
%H A135552 G. C. Greubel, <a href="/A135552/b135552.txt">Table of n, a(n) for the first 25 rows</a>
%F A135552 Coefficients of polynomials defined by recurrence: c0=2; p(x, n) = (2 + c0 - x)*p(x, n - 1) + (-1 - c0 (2 - x))*p(x, n - 2) + c0*p(x, n - 3).
%e A135552 {1},
%e A135552 {4, -1},
%e A135552 {11, -6, 1},
%e A135552 {26, -22, 8, -1},
%e A135552 {57, -64, 37, -10, 1},
%e A135552 {120, -163, 130, -56, 12, -1},
%e A135552 {247, -382, 386, -232, 79, -14, 1},
%e A135552 {502, -848, 1024, -794, 378, -106, 16, -1},
%e A135552 {1013, -1816, 2510, -2380, 1471, -576, 137, -18, 1},
%e A135552 {2036, -3797, 5812, -6476, 4944, -2517, 834, -172, 20, -1},
%e A135552 {4083, -7814, 12911, -16384, 14893, -9402, 4048, -1160, 211, -22, 1}
%t A135552 Clear[p, x, n, a]; p[x, -1] = 0; p[x, 0] = 1; p[x, 1] = 4 - x; p[x_, n_] := p[x, n] = (4 - x)*p[x, n - 1] + (-5 + 2*x)*p[x, n - 2] + 2*p[x, n - 3]; Table[ExpandAll[p[x, n]], {n, 0, 10}]; a = Table[CoefficientList[p[x, n], x], {n, 0, 10}]; Flatten[a]
%Y A135552 Cf. A136674, A109954.
%K A135552 tabl,sign
%O A135552 1,2
%A A135552 _Roger L. Bagula_, Apr 08 2008
%E A135552 New name from _Ralf Stephan_, Jan 03 2014