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 A232628 #14 Dec 16 2013 09:46:23
%S A232628 1,1,1,2,2,1,2,2,1,1,2,1,1,2,1,2,2,1,1,1,1,2,1,2,1,2,2,1,2,2,2,2,2,2,
%T A232628 1,1,2,1,1,1,1,1,1,2,1,2,2,1,1,1,1,1,1,1,1,2,1,2,1,1,1,1,1,2,2,1
%N A232628 Denominators of the triangle of polynomial coefficients P(0,x)=1, 2*P(n)=(1+x)*((1+x)^(n-1)+x^(n-1)).
%C A232628 See A233508.
%e A232628 1,
%e A232628 1, 1,
%e A232628 2, 2, 1,
%e A232628 2, 2, 1, 1,
%e A232628 2, 1, 1, 2, 1,
%e A232628 2, 2, 1, 1, 1, 1, etc.
%t A232628 p[n_] := (1+x)*((1+x)^(n-1)+x^(n-1))/2; t[n_, k_] := Coefficient[p[n], x, k] // Denominator; Table[t[n, k], {n, 0, 10 }, {k, 0, n}] // Flatten
%Y A232628 Cf. A233508 (numerators).
%K A232628 nonn,tabl,frac
%O A232628 0,4
%A A232628 _Jean-François Alcover_ and _Paul Curtz_, Dec 16 2013