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 A210791 #13 Jan 26 2020 20:55:36 %S A210791 1,1,1,1,2,2,1,3,7,3,1,4,17,14,5,1,5,36,42,30,8,1,6,72,104,111,58,13, %T A210791 1,7,141,233,329,251,111,21,1,8,275,494,862,848,553,206,34,1,9,538, %U A210791 1016,2097,2479,2112,1158,377,55,1,10,1058,2056,4870,6608,6875 %N A210791 Triangle of coefficients of polynomials u(n,x) jointly generated with A210792; see the Formula section. %C A210791 Row n starts with 1 and ends with F(n), where F=A000045 (Fibonacci numbers). %C A210791 Column 2: 1,2,3,4,5,6,7,8,... %C A210791 Row sums: A007051. %C A210791 Alternating row sums: A000129. %C A210791 For a discussion and guide to related arrays, see A208510. %C A210791 Subtriangle of the triangle given by (1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 1, 1, -1, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - _Philippe Deléham_, Mar 29 2012 %F A210791 u(n,x) = u(n-1,x) + x*v(n-1,x), %F A210791 v(n,x) = (x-1)*u(n-1,x) + (x+2)*v(n-1,x), %F A210791 where u(1,x)=1, v(1,x)=1. %F A210791 From _Philippe Deléham_, Mar 29 2012: (Start) %F A210791 As DELTA-triangle T(n,k) with 0 <= k <= n: %F A210791 G.f.: (1 - 2*x - y*x + 2*y*x^2 - y^2*x^2)/(1 - 3*x - y*x + 2*x^2 + 2*y*x^2 - y^2*x^2). %F A210791 T(n,k) = 3*T(n-1,k) + T(n-1,k-1) - 2*T(n-2,k) - 2*T(n-2,k-1) + T(n-2,k-2), T(0,0) = T(1,0) = T(2,0) = T(2,1) = 1, T(1,1) = T(2,2) = 0 and T(n,k) = 0 if k < 0 or if k > n. (End) %e A210791 First five rows: %e A210791 1; %e A210791 1, 1; %e A210791 1, 2, 2; %e A210791 1, 3, 7, 3; %e A210791 1, 4, 17, 14, 5; %e A210791 First three polynomials u(n,x): %e A210791 1 %e A210791 1 + x %e A210791 1 + 2x + 2x^2. %e A210791 From _Philippe Deléham_, Mar 29 2012: (Start) %e A210791 (1, 0, 0, 2, 0, 0, 0, ...) DELTA (0, 1, 1, -1, 0, 0, 0, ...) begins: %e A210791 1; %e A210791 1, 0; %e A210791 1, 1, 0; %e A210791 1, 2, 2, 0; %e A210791 1, 3, 7, 3, 0; %e A210791 1, 4, 17, 14, 5, 0; %e A210791 1, 5, 36, 42, 30, 8, 0; %e A210791 1, 6, 72, 104, 111, 58, 13, 0; (End) %t A210791 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210791 u[n_, x_] := u[n - 1, x] + (x + j)*v[n - 1, x] + c; %t A210791 d[x_] := h + x; e[x_] := p + x; %t A210791 v[n_, x_] := d[x]*u[n - 1, x] + e[x]*v[n - 1, x] + f; %t A210791 j = 0; c = 0; h = -1; p = 2; f = 0; %t A210791 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210791 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210791 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210791 TableForm[cu] %t A210791 Flatten[%] (* A210791 *) %t A210791 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210791 TableForm[cv] %t A210791 Flatten[%] (* A210792 *) %t A210791 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A007051 *) %t A210791 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A000244 *) %t A210791 Table[u[n, x] /. x -> -1, {n, 1, z}] (* A001129 *) %t A210791 Table[v[n, x] /. x -> -1, {n, 1, z}] (* A001333 *) %Y A210791 Cf. A210792, A208510. %K A210791 nonn,tabl %O A210791 1,5 %A A210791 _Clark Kimberling_, Mar 26 2012