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 A203149 #5 Mar 30 2012 18:58:05
%S A203149 1,10,276,22496,5477312,3995536896,8740106791936,57347917373194240,
%T A203149 1128805788065906196480,66655379003341682687344640,
%U A203149 11807831483305724934163060490240,6275171273199511284527725270165094400,10004652813703079731923092657993740504268800
%N A203149 (n-1)-st elementary symmetric function of {2,8,26,80,242,...,-1+3^n}.
%t A203149 f[k_] := 3^k - 1; t[n_] := Table[f[k], {k, 1, n}]
%t A203149 a[n_] := SymmetricPolynomial[n - 1, t[n]]
%t A203149 Table[a[n], {n, 1, 16}] (* A203149 *)
%Y A203149 Cf. A203148.
%K A203149 nonn
%O A203149 1,2
%A A203149 _Clark Kimberling_, Dec 29 2011