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 A210801 #5 Mar 30 2012 18:58:17 %S A210801 1,3,1,6,5,2,12,15,10,3,21,39,37,19,5,39,90,111,81,35,8,66,198,300, %T A210801 281,171,64,13,120,414,750,855,659,346,115,21,201,846,1776,2391,2230, %U A210801 1474,684,205,34,363,1683,4044,6255,6828,5441,3170,1323,362,55 %N A210801 Triangle of coefficients of polynomials u(n,x) jointly generated with A210802; see the Formula section. %C A210801 Row n ends with F(n), where F=A000045 (Fibonacci numbers). %C A210801 Row sums: A003462 %C A210801 Alternating row sums: 1,2,3,4,5,6,7,8,... %C A210801 For a discussion and guide to related arrays, see A208510. %F A210801 u(n,x)=u(n-1,x)+(x+1)*v(n-1,x)+1, %F A210801 v(n,x)=(x+2)*u(n-1,x)+(x-1)*v(n-1,x)+1, %F A210801 where u(1,x)=1, v(1,x)=1. %e A210801 First five rows: %e A210801 1 %e A210801 3....1 %e A210801 6....5....2 %e A210801 12...15...10...3 %e A210801 21...39...37...19...5 %e A210801 First three polynomials u(n,x): 1, 3 + x, 6 + 5x + 2x^2. %t A210801 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210801 u[n_, x_] := u[n - 1, x] + (x + j)*v[n - 1, x] + c; %t A210801 d[x_] := h + x; e[x_] := p + x; %t A210801 v[n_, x_] := d[x]*u[n - 1, x] + e[x]*v[n - 1, x] + f; %t A210801 j = 1; c = 1; h = 2; p = -1; f = 1; %t A210801 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210801 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210801 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210801 TableForm[cu] %t A210801 Flatten[%] (* A210801 *) %t A210801 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210801 TableForm[cv] %t A210801 Flatten[%] (* A210802 *) %t A210801 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A003462 *) %t A210801 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A003462 *) %t A210801 Table[u[n, x] /. x -> -1, {n, 1, z}] (* A000027 *) %t A210801 Table[v[n, x] /. x -> -1, {n, 1, z}] (* A077898 *) %Y A210801 Cf. A210802, A208510. %K A210801 nonn,tabl %O A210801 1,2 %A A210801 _Clark Kimberling_, Mar 27 2012