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 A203230 #7 Oct 15 2013 14:38:45
%S A203230 1,4,7,24,33,108,135,432,513,1620,1863,5832,6561,20412,22599,69984,
%T A203230 76545,236196,255879,787320,846369,2598156,2775303,8503056,9034497,
%U A203230 27634932,29229255,89282088,94065057,286978140,301327047,918330048
%N A203230 (n-1)-st elementary symmetric function of the first n terms of A010684.
%F A203230 Conjecture: a(n)=6*a(n-2)-9*a(n-4) with G.f. x*(1+4*x+x^2) / (-1+3*x^2)^2 . - _R. J. Mathar_, Oct 15 2013
%t A203230 r = {1, 3, 1, 3, 1, 3};
%t A203230 s = Flatten[{r, r, r, r, r, r, r, r, r}];
%t A203230 t[n_] := Part[s, Range[n]]
%t A203230 a[n_] := SymmetricPolynomial[n - 1, t[n]]
%t A203230 Table[a[n], {n, 1, 32}] (* A203230 *)
%Y A203230 Cf. A010684, A203231, A120908 (bisection?).
%K A203230 nonn
%O A203230 1,2
%A A203230 _Clark Kimberling_, Dec 30 2011