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 A203529 #13 Jan 13 2025 15:05:31 %S A203529 1,5,175,44100,60913125,427756329000,20552836095792000, %T A203529 6952965728817588480000,11895516181976215338950400000, %U A203529 99606443887767729350960121600000000,5830034964946921746536425070101217280000000 %N A203529 a(n) = A203527(n)/A000178(n-1); A000178 = (superfactorials). %C A203529 It is conjectured that every term is an integer. %t A203529 t = Table[If[PrimeQ[k], 0, k], {k, 1, 100}]; %t A203529 nonprime = Rest[Union[t]] (* A018252 *) %t A203529 f[j_] := nonprime[[j]]; z = 20; %t A203529 v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}] %t A203529 d[n_] := Product[(i - 1)!, {i, 1, n}] (* A000178 *) %t A203529 Table[v[n], {n, 1, z}] (* A203527 *) %t A203529 Table[v[n + 1]/v[n], {n, 1, z - 1}] (* A203528 *) %t A203529 Table[v[n]/d[n], {n, 1, 20}] (* A203529 *) %Y A203529 Cf. A000178, A203527, A203528, A018252, A093883, A203417. %K A203529 nonn %O A203529 1,2 %A A203529 _Clark Kimberling_, Jan 03 2012