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 A119305 #10 Mar 01 2017 11:04:46
%S A119305 1,-4,1,0,-7,1,0,15,-10,1,0,-13,39,-13,1,0,4,-80,72,-16,1,0,0,95,-228,
%T A119305 114,-19,1,0,0,-66,462,-484,165,-22,1,0,0,25,-630,1375,-875,225,-25,1,
%U A119305 0,0,-4,588,-2772,3185,-1428,294,-28,1,0,0,0,-372,4092,-8463,6324,-2170,372
%N A119305 Riordan array (1-4x, x(1-x)^3).
%C A119305 Inverse of number triangle binomial(4n-k, n-k), A119304. Row sums are A119306.
%H A119305 Indranil Ghosh, <a href="/A119305/b119305.txt">Rows 0..101, flattened</a>
%F A119305 Number triangle T(n,k) = (C(3k, n-k) + 4*C(3k, n-k-1))(-1)^(n-k).
%e A119305 Triangle begins
%e A119305 1;
%e A119305 -4, 1;
%e A119305 0, -7, 1;
%e A119305 0, 15, -10, 1;
%e A119305 0, -13, 39, -13, 1;
%e A119305 0, 4, -80, 72, -16, 1;
%e A119305 0, 0, 95, -228, 114, -19, 1;
%t A119305 Flatten[Table[(Binomial[3k,n-k]+4Binomial[3k,n-k-1])*(-1)^(n-k),{n,0,11},{k,0,n}]] (* _Indranil Ghosh_, Feb 26 2017 *)
%o A119305 (PARI) tabl(nn) = {for (n=0,nn,for (k=0,n,print1((binomial(3*k,n-k)+4*binomial(3*k,n-k-1))*(-1)^(n-k),", "););print(););} \\ _Indranil Ghosh_, Feb 26 2017
%K A119305 easy,sign,tabl
%O A119305 0,2
%A A119305 _Paul Barry_, May 13 2006