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 A209760 #8 Mar 30 2012 18:58:15 %S A209760 1,1,3,1,3,8,1,3,11,21,1,3,11,38,55,1,3,11,41,124,144,1,3,11,41,150, %T A209760 389,377,1,3,11,41,153,533,1187,987,1,3,11,41,153,568,1838,3549,2584, %U A209760 1,3,11,41,153,571,2084,6168,10447,6765,1,3,11,41,153,571,2128 %N A209760 Triangle of coefficients of polynomials v(n,x) jointly generated with A209759; see the Formula section. %C A209760 Limiting row: A001835 %C A209760 Coefficient of x^n in v(n,x): even-indexed Fibonacci numbers %C A209760 For a discussion and guide to related arrays, see A208510. %F A209760 u(n,x)=x*u(n-1,x)+(x+1)*v(n-1,x), %F A209760 v(n,x)=x*u(n-1,x)+2x*v(n-1,x)+1, %F A209760 where u(1,x)=1, v(1,x)=1. %e A209760 First five rows: %e A209760 1 %e A209760 1...3 %e A209760 1...3...8 %e A209760 1...3...11...21 %e A209760 1...3...11...38...55 %e A209760 First three polynomials v(n,x): 1, 1 + 3x , 1 + 3x + 8x^2. %t A209760 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A209760 u[n_, x_] := x*u[n - 1, x] + (x + 1)*v[n - 1, x]; %t A209760 v[n_, x_] := x*u[n - 1, x] + 2 x*v[n - 1, x] + 1; %t A209760 Table[Expand[u[n, x]], {n, 1, z/2}] %t A209760 Table[Expand[v[n, x]], {n, 1, z/2}] %t A209760 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A209760 TableForm[cu] %t A209760 Flatten[%] (* A209759 *) %t A209760 Table[Expand[v[n, x]], {n, 1, z}] %t A209760 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A209760 TableForm[cv] %t A209760 Flatten[%] (* A209760 *) %Y A209760 Cf. A208510. %K A209760 nonn,tabl %O A209760 1,3 %A A209760 _Clark Kimberling_, Mar 14 2012