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 A207614 #5 Mar 30 2012 18:58:13 %S A207614 1,2,5,1,11,5,1,23,16,6,1,47,44,23,7,1,95,112,74,31,8,1,191,272,216, %T A207614 113,40,9,1,383,640,592,368,162,50,10,1,767,1472,1552,1112,579,222,61, %U A207614 11,1,1535,3328,3936,3184,1902,861,294,73,12,1,3071,7424,9728 %N A207614 Triangle of coefficients of polynomials u(n,x) jointly generated with A207615; see the Formula section. %F A207614 u(n,x)=u(n-1,x)+v(n-1,x), v(n,x)=u(n-1,x)+(x+1)v(n-1,x)+1, %F A207614 where u(1,x)=1, v(1,x)=1. %e A207614 First five rows: %e A207614 1 %e A207614 2 %e A207614 5....1 %e A207614 11...5....1 %e A207614 23...16...6...1 %t A207614 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A207614 u[n_, x_] := u[n - 1, x] + v[n - 1, x] %t A207614 v[n_, x_] := u[n - 1, x] + (x + 1)*v[n - 1, x] + 1 %t A207614 Table[Factor[u[n, x]], {n, 1, z}] %t A207614 Table[Factor[v[n, x]], {n, 1, z}] %t A207614 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A207614 TableForm[cu] %t A207614 Flatten[%] (* A207614 *) %t A207614 Table[Expand[v[n, x]], {n, 1, z}] %t A207614 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A207614 TableForm[cv] %t A207614 Flatten[%] (* A207615 *) %Y A207614 Cf. A207615. %K A207614 nonn,tabf %O A207614 1,2 %A A207614 _Clark Kimberling_, Feb 20 2012