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 A207537 #24 Feb 03 2021 17:45:43 %S A207537 1,2,1,4,3,8,8,1,16,20,5,32,48,18,1,64,112,56,7,128,256,160,32,1,256, %T A207537 576,432,120,9,512,1280,1120,400,50,1,1024,2816,2816,1232,220,11,2048, %U A207537 6144,6912,3584,840,72,1,4096,13312,16640,9984,2912,364,13 %N A207537 Triangle of coefficients of polynomials u(n,x) jointly generated with A207538; see Formula section. %C A207537 Another version in A201701. - _Philippe Deléham_, Mar 03 2012 %C A207537 Subtriangle of the triangle given by (1, 1, 0, 0, 0, 0, 0, 0, 0, 0, ...) DELTA (0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - _Philippe Deléham_, Mar 03 2012 %C A207537 Columns: A011782, A001792, A001793, A001794, A006974, A006975, A006976. - _Philippe Deléham_, Mar 03 2012 %C A207537 Diagonal sums: A052980. - _Philippe Deléham_, Mar 03 2012 %F A207537 u(n,x) = u(n-1,x) + (x+1)*v(n-1,x), v(n,x) = u(n-1,x) + v(n-1,x), where u(1,x)=1, v(1,x)=1. Also, A207537 = |A028297|. %F A207537 T(n,k) = 2*T(n-1,k) + T(n-2,k-1). - _Philippe Deléham_, Mar 03 2012 %F A207537 G.f.: -(1+x*y)*x*y/(-1+2*x+x^2*y). - _R. J. Mathar_, Aug 11 2015 %F A207537 T(n, k) = [x^k] hypergeom([-n/2, -n/2 + 1/2], [1/2], x + 1) provided offset is set to 0 and 1 prepended. - _Peter Luschny_, Feb 03 2021 %e A207537 First seven rows: %e A207537 1; %e A207537 2, 1; %e A207537 4, 3; %e A207537 8, 8, 1; %e A207537 16, 20, 5, %e A207537 32, 48, 18, 1; %e A207537 64, 112, 56, 7; %e A207537 From _Philippe Deléham_, Mar 03 2012: (Start) %e A207537 Triangle A201701 begins: %e A207537 1; %e A207537 1, 0; %e A207537 2, 1, 0; %e A207537 4, 3, 0, 0; %e A207537 8, 8, 1, 0, 0; %e A207537 16, 20, 5, 0, 0, 0; %e A207537 32, 48, 18, 1, 0, 0, 0; %e A207537 64, 112, 56, 7, 0, 0, 0, 0; %e A207537 ... (End) %t A207537 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A207537 u[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x] %t A207537 v[n_, x_] := u[n - 1, x] + v[n - 1, x] %t A207537 Table[Factor[u[n, x]], {n, 1, z}] %t A207537 Table[Factor[v[n, x]], {n, 1, z}] %t A207537 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A207537 TableForm[cu] %t A207537 Flatten[%] (* A207537, |A028297| *) %t A207537 Table[Expand[v[n, x]], {n, 1, z}] %t A207537 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A207537 TableForm[cv] %t A207537 Flatten[%] (* A207538, |A133156| *) %t A207537 (* Prepending 1 and with offset 0: *) %t A207537 Tpoly[n_] := HypergeometricPFQ[{-n/2, -n/2 + 1/2}, {1/2}, x + 1]; %t A207537 Table[CoefficientList[Tpoly[n], x], {n, 0, 12}] // Flatten (* _Peter Luschny_, Feb 03 2021 *) %Y A207537 Cf. A028297, A207538, A133156. %K A207537 nonn,tabf %O A207537 1,2 %A A207537 _Clark Kimberling_, Feb 18 2012