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 A209161 #5 Mar 30 2012 18:58:15 %S A209161 1,1,4,1,6,10,1,8,24,28,1,10,42,88,76,1,12,64,188,300,208,1,14,90,336, %T A209161 760,984,568,1,16,120,540,1560,2880,3136,1552,1,18,154,808,2820,6672, %U A209161 10416,9792,4240,1,20,192,1148,4676,13392,26880,36384,30096 %N A209161 Triangle of coefficients of polynomials v(n,x) jointly generated with A209160; see the Formula section. %C A209161 For a discussion and guide to related arrays, see A208510. %F A209161 u(n,x)=u(n-1,x)+(x+1)*v(n-1,x), %F A209161 v(n,x)=2x*u(n-1,x)+2x*v(n-1,x)+1, %F A209161 where u(1,x)=1, v(1,x)=1. %e A209161 First five rows: %e A209161 1 %e A209161 1...4 %e A209161 1...6...10 %e A209161 1...8...24...28 %e A209161 1...10...42...88...76 %e A209161 First three polynomials v(n,x): 1, 1 + 4x, 1 + 6x + 10x^2. %t A209161 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A209161 u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x]; %t A209161 v[n_, x_] := 2 x*u[n - 1, x] + 2 x*v[n - 1, x] + 1; %t A209161 Table[Expand[u[n, x]], {n, 1, z/2}] %t A209161 Table[Expand[v[n, x]], {n, 1, z/2}] %t A209161 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A209161 TableForm[cu] %t A209161 Flatten[%] (* A209160 *) %t A209161 Table[Expand[v[n, x]], {n, 1, z}] %t A209161 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A209161 TableForm[cv] %t A209161 Flatten[%] (* A209161 *) %Y A209161 Cf. A209160, A208510. %K A209161 nonn,tabl %O A209161 1,3 %A A209161 _Clark Kimberling_, Mar 07 2012