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 A210753 #5 Mar 30 2012 18:58:17 %S A210753 1,2,2,3,7,4,4,16,20,8,5,30,61,52,16,6,50,146,198,128,32,7,77,301,575, %T A210753 584,304,64,8,112,560,1408,1992,1616,704,128,9,156,966,3060,5641,6328, %U A210753 4272,1600,256,10,210,1572,6084,14002,20330,18880,10912,3584 %N A210753 Triangle of coefficients of polynomials u(n,x) jointly generated with A210754; see the Formula section. %C A210753 Row n starts with n and ends with 2^(n-1). %C A210753 Row sums: A007070 %C A210753 Alternating row sums: 1,0,0,0,0,0,0,0,0,.... %C A210753 For a discussion and guide to related arrays, see A208510. %F A210753 u(n,x)=(x+1)*u(n-1,x)+x*v(n-1,x)+1, %F A210753 v(n,x)=(x+1)*u(n-1,x)+(x+1)*v(n-1,x)+1, %F A210753 where u(1,x)=1, v(1,x)=1. %e A210753 First five rows: %e A210753 1 %e A210753 2...2 %e A210753 3...7....4 %e A210753 4...16...20...8 %e A210753 5...30...61...52...16 %e A210753 First three polynomials u(n,x): 1, 2 + 2x, 3 + 7x + 4x^2. %t A210753 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210753 u[n_, x_] := (x + 1)*u[n - 1, x] + x*v[n - 1, x] + 1; %t A210753 v[n_, x_] := (x + 1)*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1; %t A210753 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210753 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210753 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210753 TableForm[cu] %t A210753 Flatten[%] (* A210753 *) %t A210753 Table[Expand[v[n, x]], {n, 1, z}] %t A210753 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210753 TableForm[cv] %t A210753 Flatten[%] (* A210754 *) %t A210753 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A007070 *) %t A210753 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A035344 *) %Y A210753 Cf. A210754, A208510. %K A210753 nonn,tabl %O A210753 1,2 %A A210753 _Clark Kimberling_, Mar 25 2012