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 A210756 #5 Mar 30 2012 18:58:17 %S A210756 1,3,2,6,10,5,10,30,33,12,15,70,127,100,29,21,140,371,472,291,70,28, %T A210756 252,910,1656,1624,822,169,36,420,1974,4800,6640,5294,2273,408,45,660, %U A210756 3906,12144,22166,24702,16589,6184,985,55,990,7194,27720,63954 %N A210756 Triangle of coefficients of polynomials v(n,x) jointly generated with A210755; see the Formula section. %C A210756 Column 1: triangular numbers, A000217 %C A210756 Coefficient of v(n,x): A000129(n) %C A210756 Row sums: A002450 %C A210756 Alternating row sums: 1,1,1,1,1,1,1,1,1,... %C A210756 For a discussion and guide to related arrays, see A208510. %F A210756 u(n,x)=(x+1)*u(n-1,x)+2x*v(n-1,x)+1, %F A210756 v(n,x)=(x+1)*u(n-1,x)+(x+1)*v(n-1,x)+1, %F A210756 where u(1,x)=1, v(1,x)=1. %e A210756 First five rows: %e A210756 1 %e A210756 3....2 %e A210756 6....10...5 %e A210756 10...30...33....12 %e A210756 15...70...127...100...29 %e A210756 First three polynomials v(n,x): 1, 3 + 2x, 6 + 10x + 5x^2 %t A210756 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210756 u[n_, x_] := (x + 1)*u[n - 1, x] + 2 x*v[n - 1, x] + 1; %t A210756 v[n_, x_] := (x + 1)*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1; %t A210756 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210756 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210756 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210756 TableForm[cu] %t A210756 Flatten[%] (* A210755 *) %t A210756 Table[Expand[v[n, x]], {n, 1, z}] %t A210756 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210756 TableForm[cv] %t A210756 Flatten[%] (* A210756 *) %t A210756 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A002450 *) %t A210756 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A002450 *) %Y A210756 Cf. A210755, A208510. %K A210756 nonn,tabl %O A210756 1,2 %A A210756 _Clark Kimberling_, Mar 25 2012