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 A209163 #5 Mar 30 2012 18:58:15 %S A209163 1,2,3,3,9,5,4,20,26,11,5,38,82,71,21,6,65,204,279,176,43,7,103,439, %T A209163 849,845,425,85,8,154,854,2192,3050,2386,990,171,9,220,1540,5034,9174, %U A209163 9940,6396,2267,341,10,303,2616,10578,24232,34102,30228,16521 %N A209163 Triangle of coefficients of polynomials v(n,x) jointly generated with A209162; see the Formula section. %C A209163 Alternating row sums: 1,-1,-1,-1,-,1-,1-,1,-1,... %C A209163 For a discussion and guide to related arrays, see A208510. %F A209163 u(n,x)=u(n-1,x)+(x+1)*v(n-1,x), %F A209163 v(n,x)=2x*u(n-1,x)+(x+1)*v(n-1,x)+1, %F A209163 where u(1,x)=1, v(1,x)=1. %e A209163 First five rows: %e A209163 1 %e A209163 2...3 %e A209163 3...9...5 %e A209163 4...20...26...11 %e A209163 5...38...82...71...21 %e A209163 First three polynomials v(n,x): 1, 2 + 3x, 3 + 9x + 5x^2. %t A209163 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A209163 u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x]; %t A209163 v[n_, x_] := 2 x*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1; %t A209163 Table[Expand[u[n, x]], {n, 1, z/2}] %t A209163 Table[Expand[v[n, x]], {n, 1, z/2}] %t A209163 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A209163 TableForm[cu] %t A209163 Flatten[%] (* A209162 *) %t A209163 Table[Expand[v[n, x]], {n, 1, z}] %t A209163 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A209163 TableForm[cv] %t A209163 Flatten[%] (* A209163 *) %Y A209163 Cf. A209162, A208510. %K A209163 nonn,tabl %O A209163 1,2 %A A209163 _Clark Kimberling_, Mar 07 2012