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 A208527 #5 Mar 30 2012 18:58:13 %S A208527 1,1,4,1,4,10,1,4,12,28,1,4,14,40,76,1,4,16,52,124,208,1,4,18,64,176, %T A208527 384,568,1,4,20,76,232,592,1168,1552,1,4,22,88,292,832,1936,3520,4240, %U A208527 1,4,24,100,356,1104,2880,6240,10512,11584,1,4,26,112,424,1408 %N A208527 Triangle of coefficients of polynomials v(n,x) jointly generated with A208526; see the Formula section. %F A208527 u(n,x)=u(n-1,x)+x*v(n-1,x), %F A208527 v(n,x)=2x*u(n-1,x)+2x*v(n-1,x)+1, %F A208527 where u(1,x)=1, v(1,x)=1. %e A208527 First five rows: %e A208527 1 %e A208527 1...4 %e A208527 1...4...10 %e A208527 1...4...12...28 %e A208527 1...4...14...40...76 %e A208527 First five polynomials v(n,x): %e A208527 1 %e A208527 1 + 4x %e A208527 1 + 4x + 10x^2 %e A208527 1 + 4x + 12x^2 + 28x^3 %e A208527 1 + 4x + 14x^2 + 40x^3 + 76x^4 %t A208527 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A208527 u[n_, x_] := u[n - 1, x] + x*v[n - 1, x]; %t A208527 v[n_, x_] := 2 x*u[n - 1, x] + 2 x*v[n - 1, x] + 1; %t A208527 Table[Expand[u[n, x]], {n, 1, z/2}] %t A208527 Table[Expand[v[n, x]], {n, 1, z/2}] %t A208527 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A208527 TableForm[cu] %t A208527 Flatten[%] (* A208526 *) %t A208527 Table[Expand[v[n, x]], {n, 1, z}] %t A208527 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A208527 TableForm[cv] %t A208527 Flatten[%] (* A208527 *) %Y A208527 Cf. A208526. %K A208527 nonn,tabl %O A208527 1,3 %A A208527 _Clark Kimberling_, Feb 29 2012