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 A203429 #10 Sep 28 2023 02:03:48
%S A203429 -2,27,-576,16875,-629856,28588707,-1528823808,94143178827,
%T A203429 -6561000000000,510526328421483,-43873901280755712,
%U A203429 4127185885192141707,-421812572812955541504,46542953399578857421875
%N A203429 a(n) = w(n+1)/(3*w(n)), where w = A203428.
%H A203429 G. C. Greubel, <a href="/A203429/b203429.txt">Table of n, a(n) for n = 1..250</a>
%F A203429 a(n) = -(-3)^(n-1) * (n+1)^n. - _G. C. Greubel_, Sep 28 2023
%t A203429 (* First program *)
%t A203429 f[j_]:= 1/(3*j); z = 16;
%t A203429 v[n_]:= Product[Product[f[k] - f[j], {j,k-1}], {k,2,n}]
%t A203429 1/Table[v[n], {n,z}] (* A203428 *)
%t A203429 Table[v[n]/(3*v[n+1]), {n,z}] (* A203429 *)
%t A203429 (* Second program *)
%t A203429 Table[-(-3)^(n-1)*(n+1)^n, {n,20}] (* _G. C. Greubel_, Sep 28 2023 *)
%o A203429 (Magma) [-(-3)^(n-1)*(n+1)^n: n in [1..20]]; // _G. C. Greubel_, Sep 28 2023
%o A203429 (SageMath) [-(-3)^(n-1)*(n+1)^n for n in range(1,21)] # _G. C. Greubel_, Sep 28 2023
%Y A203429 Cf. A203427, A203428.
%K A203429 sign
%O A203429 1,1
%A A203429 _Clark Kimberling_, Jan 02 2012