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 A210871 #5 Mar 31 2012 20:30:51 %S A210871 1,1,2,1,1,3,1,3,2,5,1,2,7,3,8,1,4,5,15,5,13,1,3,12,10,30,8,21,1,5,9, %T A210871 31,20,58,13,34,1,4,18,22,73,38,109,21,55,1,6,14,54,51,162,71,201,34, %U A210871 89,1,5,25,40,145,111,344,130,365,55,144,1,7,20,85,105,361,233 %N A210871 Triangle of coefficients of polynomials v(n,x) jointly generated with A210870; see the Formula section. %C A210871 Row n, for n>2, starts with 1 and A028242(n) and ends with F(n-1) and F(n+1), where F=A000045 (Fibonacci numbers). %C A210871 Row sums: A001045 %C A210871 Alternating row sums: A077925 %C A210871 For a discussion and guide to related arrays, see A208510. %F A210871 u(n,x)=u(n-1,x)+x*v(n-1,x), %F A210871 v(n,x)=(x+1)*u(n-1,x)+(x-1)*v(n-1,x)+1, %F A210871 where u(1,x)=1, v(1,x)=1. %e A210871 First six rows: %e A210871 1 %e A210871 1...2 %e A210871 1...1...3 %e A210871 1...3...2....5 %e A210871 1...2...7....3....8 %e A210871 1...4...5....15...5...13 %e A210871 First three polynomials v(n,x): 1, 1 + 2x, 1 + x + 3x^2 %t A210871 u[1, x_] := 1; v[1, x_] := 1; z = 14; %t A210871 u[n_, x_] := u[n - 1, x] + x*v[n - 1, x]; %t A210871 v[n_, x_] := (x + 1)*u[n - 1, x] + (x - 1)*v[n - 1, x] + 1; %t A210871 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210871 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210871 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210871 TableForm[cu] %t A210871 Flatten[%] (* A210870 *) %t A210871 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210871 TableForm[cv] %t A210871 Flatten[%] (* A210871 *) %t A210871 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A000975 *) %t A210871 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A001045 *) %t A210871 Table[u[n, x] /. x -> -1, {n, 1, z}] (* A113954 *) %t A210871 Table[v[n, x] /. x -> -1, {n, 1, z}] (* A077925 *) %Y A210871 Cf. A210870, A208510. %K A210871 nonn,tabl %O A210871 1,3 %A A210871 _Clark Kimberling_, Mar 29 2012