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 A209168 #5 Mar 30 2012 18:58:15 %S A209168 1,2,1,4,6,3,7,16,17,7,12,37,56,47,17,20,78,154,182,128,41,33,156,378, %T A209168 574,565,344,99,54,301,864,1590,1995,1697,915,239,88,566,1877,4048, %U A209168 6118,6605,4973,2413,577,143,1044,3927,9693,17073,22128,21093 %N A209168 Triangle of coefficients of polynomials u(n,x) jointly generated with A209169; see the Formula section. %C A209168 Row n begins with F(n+2)-1, where F=A000045 (Fibonacci numbers). %C A209168 Alternating row sums: 1,1,1,1,1,1,1,1,1,1,1,1,1,1,... %C A209168 For a discussion and guide to related arrays, see A208510. %F A209168 u(n,x)=u(n-1,x)+(x+1)*v(n-1,x), %F A209168 v(n,x)=(x+1)*u(n-1,x)+2x*v(n-1,x)+1, %F A209168 where u(1,x)=1, v(1,x)=1. %e A209168 First five rows: %e A209168 1 %e A209168 2....1 %e A209168 4....6....3 %e A209168 7....16...17...7 %e A209168 12...37...56...47...17 %e A209168 First three polynomials v(n,x): 1, 2 + x, 4 + 6x + 3x^2. %t A209168 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A209168 u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x]; %t A209168 v[n_, x_] := (x + 1)*u[n - 1, x] + 2 x*v[n - 1, x] + 1; %t A209168 Table[Expand[u[n, x]], {n, 1, z/2}] %t A209168 Table[Expand[v[n, x]], {n, 1, z/2}] %t A209168 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A209168 TableForm[cu] %t A209168 Flatten[%] (* A209168 *) %t A209168 Table[Expand[v[n, x]], {n, 1, z}] %t A209168 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A209168 TableForm[cv] %t A209168 Flatten[%] (* A209169 *) %Y A209168 Cf. A209169, A208510. %K A209168 nonn,tabl %O A209168 1,2 %A A209168 _Clark Kimberling_, Mar 08 2012