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 A210038 #4 Mar 30 2012 18:58:16 %S A210038 1,3,1,7,4,1,15,12,5,1,31,32,18,6,1,63,80,56,25,7,1,127,192,160,88,33, %T A210038 8,1,255,448,432,280,129,42,9,1,511,1024,1120,832,450,180,52,10,1, %U A210038 1023,2304,2816,2352,1452,681,242,63,11,1,2047,5120,6912,6400 %N A210038 Triangle of coefficients of polynomials v(n,x) jointly generated with A210037; see the Formula section. %C A210038 For a discussion and guide to related arrays, see A208510. %F A210038 u(n,x)=u(n-1,x)+v(n-1,x)+1, %F A210038 v(n,x)=u(n-1,x)+x*v(n-1,x)+1, %F A210038 where u(1,x)=1, v(1,x)=1. %e A210038 First five rows: %e A210038 1 %e A210038 3....1 %e A210038 7....4....1 %e A210038 15...12...5....1 %e A210038 31...32...18...6...1 %e A210038 First three polynomials v(n,x): 1, 3 + x , 7 + 4x + x^2. %t A210038 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210038 u[n_, x_] := u[n - 1, x] + v[n - 1, x] + 1; %t A210038 v[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x] + 1; %t A210038 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210038 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210038 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210038 TableForm[cu] %t A210038 Flatten[%] (* A210037 *) %t A210038 Table[Expand[v[n, x]], {n, 1, z}] %t A210038 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210038 TableForm[cv] %t A210038 Flatten[%] (* A210038 *) %Y A210038 Cf. A210037, A208510. %K A210038 nonn,tabl %O A210038 1,2 %A A210038 _Clark Kimberling_, Mar 17 2012