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 A210804 #18 Jan 27 2020 01:32:14 %S A210804 1,2,2,5,8,3,14,27,18,5,41,88,79,40,8,122,284,310,215,80,13,365,912, %T A210804 1152,980,510,156,21,1094,2917,4144,4091,2660,1150,294,34,3281,9296, %U A210804 14578,16176,12393,6752,2461,544,55,9842,29526,50436,61638,53730 %N A210804 Triangle of coefficients of polynomials v(n,x) jointly generated with A210803; see the Formula section. %C A210804 Row n ends with F(n), where F=A000045 (Fibonacci numbers). %C A210804 Column 1: A007051. %C A210804 Row sums: A000302 (powers of 4). %C A210804 Alternating row sums: 1,0,0,0,0,0,0,0,0,... %C A210804 For a discussion and guide to related arrays, see A208510. %C A210804 Essentially the same triangle as given by (2, 1/2, 3/2, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (2, -1/2, -1/2, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - _Philippe Deléham_ Jul 11 2012 %F A210804 u(n,x) = u(n-1,x) + x*v(n-1,x) + 1, v(n,x) = (x-1)*u(n-1,x) + (x+3)*v(n-1,x), where u(1,x)=1, v(1,x)=1. %F A210804 T(n,k) = 4*T(n-1,k) + T(n-1,k-1) - 3*T(n-2,k) - 2*T(n-2,k-1) + T(n-2,k-2), T(1,0) = 1, T(2,0) = T(2,1) = 2, T(3,0) = 5, T(3,1) = 8, T(3,2) = 3, T(n,k) = 0 if k < 0 or if k >= n. - _Philippe Deléham_, Jul 11 2012 %F A210804 G.f.: (-1+2*x-x*y)*x*y/(-1+4*x+x*y-3*x^2-2*x^2*y+x^2*y^2). - _R. J. Mathar_, Aug 12 2015 %e A210804 First five rows: %e A210804 1; %e A210804 2, 2; %e A210804 5, 8, 3; %e A210804 14, 27, 18, 5; %e A210804 41, 88, 79, 40, 8; %e A210804 First three polynomials v(n,x): %e A210804 1 %e A210804 2 + 2x %e A210804 5 + 8x + 3x^2 %t A210804 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210804 u[n_, x_] := u[n - 1, x] + (x + j)*v[n - 1, x] + c; %t A210804 d[x_] := h + x; e[x_] := p + x; %t A210804 v[n_, x_] := d[x]*u[n - 1, x] + e[x]*v[n - 1, x] + f; %t A210804 j = 0; c = 0; h = -1; p = 3; f = 0; %t A210804 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210804 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210804 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210804 TableForm[cu] %t A210804 Flatten[%] (* A210803 *) %t A210804 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210804 TableForm[cv] %t A210804 Flatten[%] (* A210804 *) %t A210804 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A047849 *) %t A210804 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A000302 *) %t A210804 Table[u[n, x] /. x -> -1, {n, 1, z}] (* A000007 *) %t A210804 Table[v[n, x] /. x -> -1, {n, 1, z}] (* A000007 *) %Y A210804 Cf. A210803, A208510. %K A210804 nonn,tabl %O A210804 1,2 %A A210804 _Clark Kimberling_, Mar 27 2012