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 A208753 #5 Mar 30 2012 18:58:14 %S A208753 1,1,2,1,8,1,18,4,1,32,24,1,50,80,8,1,72,200,64,1,98,420,280,16,1,128, %T A208753 784,896,160,1,162,1344,2352,864,32,1,200,2160,5376,3360,384,1,242, %U A208753 3300,11088,10560,2464,64,1,288,4840,21120,28512,11264,896,1 %N A208753 Triangle of coefficients of polynomials u(n,x) jointly generated with A208754; see the Formula section. %C A208753 For a discussion and guide to related arrays, see A208510. %F A208753 u(n,x)=u(n-1,x)+2x*v(n-1,x), %F A208753 v(n,x)=u(n-1,x)+v(n-1,x)+1, %F A208753 where u(1,x)=1, v(1,x)=1. %e A208753 First five rows: %e A208753 1 %e A208753 1...2 %e A208753 1...8 %e A208753 1...18...4 %e A208753 1...32...24 %e A208753 First five polynomials u(n,x): %e A208753 1 %e A208753 1 + 2x %e A208753 1 + 8x %e A208753 1 + 18x + 4x^2 %e A208753 1 + 32x + 24x^2 %t A208753 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A208753 u[n_, x_] := u[n - 1, x] + 2 x*v[n - 1, x]; %t A208753 v[n_, x_] := u[n - 1, x] + v[n - 1, x] + 1; %t A208753 Table[Expand[u[n, x]], {n, 1, z/2}] %t A208753 Table[Expand[v[n, x]], {n, 1, z/2}] %t A208753 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A208753 TableForm[cu] %t A208753 Flatten[%] (* A208753 *) %t A208753 Table[Expand[v[n, x]], {n, 1, z}] %t A208753 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A208753 TableForm[cv] %t A208753 Flatten[%] (* A208754 *) %Y A208753 Cf. A208754, A208510. %K A208753 nonn,tabf %O A208753 1,3 %A A208753 _Clark Kimberling_, Mar 03 2012