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 A210198 #6 Oct 17 2012 10:05:03 %S A210198 1,3,1,7,4,15,12,1,31,32,6,63,80,24,1,127,192,80,8,255,448,240,40,1, %T A210198 511,1024,672,160,10,1023,2304,1792,560,60,1,2047,5120,4608,1792,280, %U A210198 12,4095,11264,11520,5376,1120,84,1,8191,24576,28160,15360,4032 %N A210198 Triangle of coefficients of polynomials v(n,x) jointly generated with A210197; see the Formula section. %C A210198 Row sums: A005409 %C A210198 Column 1: -1+2^n %C A210198 Alternating row sums: 1, 2,3,4,5,6,..., A000027 %C A210198 For a discussion and guide to related arrays, see A208510. %F A210198 u(n,x)=u(n-1,x)+v(n-1,x)+1, %F A210198 v(n,x)=(x+1)*u(n-1,x)+v(n-1,x)+1, %F A210198 where u(1,x)=1, v(1,x)=1. %e A210198 First five rows: %e A210198 1 %e A210198 3....1 %e A210198 15...12...1 %e A210198 31...32...6 %e A210198 63...80...24...1 %e A210198 First three polynomials v(n,x): 1, 3 + x , 15 + 12x + x^2. %t A210198 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210198 u[n_, x_] := u[n - 1, x] + v[n - 1, x] + 1; %t A210198 v[n_, x_] := (x + 1)*u[n - 1, x] + v[n - 1, x] + 1; %t A210198 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210198 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210198 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210198 TableForm[cu] %t A210198 Flatten[%] (* A210197 *) %t A210198 Table[Expand[v[n, x]], {n, 1, z}] %t A210198 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210198 TableForm[cv] %t A210198 Flatten[%] (* A210198 *) %t A210198 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A048739 *) %t A210198 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A005409 *) %t A210198 Table[u[n, x] /. x -> -1, {n, 1, z}] (* A000217 *) %t A210198 Table[v[n, x] /. x -> -1, {n, 1, z}] (* A000027 *) %Y A210198 Cf. A210197, A208510. %K A210198 nonn,tabl %O A210198 1,2 %A A210198 _Clark Kimberling_, Mar 18 2012