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 A210193 #4 Mar 30 2012 18:58:16 %S A210193 1,3,6,3,10,14,3,15,40,23,3,21,90,97,32,3,28,175,301,181,41,3,36,308, %T A210193 770,728,292,50,3,45,504,1722,2346,1452,430,59,3,55,780,3486,6456, %U A210193 5686,2554,595,68,3,66,1155,6534,15774,18722,11816,4115,787,77,3 %N A210193 Triangle of coefficients of polynomials u(n,x) jointly generated with A210194; see the Formula section. %C A210193 Row sums: powers of 3 %C A210193 For a discussion and guide to related arrays, see A208510. %F A210193 u(n,x)=u(n-1,x)+v(n-1,x)+1, %F A210193 v(n,x)=2x*u(n-1,x)+(x+1)*v(n-1,x)+1, %F A210193 where u(1,x)=1, v(1,x)=1. %e A210193 First five rows: %e A210193 1 %e A210193 3 %e A210193 6....3 %e A210193 10...14...3 %e A210193 15...40...23...3 %e A210193 First three polynomials u(n,x): 1, 3, 6 + 3x. %t A210193 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210193 u[n_, x_] := u[n - 1, x] + v[n - 1, x] + 1; %t A210193 v[n_, x_] := 2 x*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1; %t A210193 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210193 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210193 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210193 TableForm[cu] %t A210193 Flatten[%] (* A210193 *) %t A210193 Table[Expand[v[n, x]], {n, 1, z}] %t A210193 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210193 TableForm[cv] %t A210193 Flatten[%] (* A210194 *) %Y A210193 Cf. A210194, A208510. %K A210193 nonn,tabf %O A210193 1,2 %A A210193 _Clark Kimberling_, Mar 18 2012