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 A203533 #13 Jan 13 2025 15:06:19 %S A203533 1,10,840,464100,1481407200,32851686067200,5186361382800998400, %T A203533 4436556151786001058816000,19667253420867342693731328000000, %U A203533 605862171333980479840975997239296000000,132207384898194165523202154782408753283072000000 %N A203533 a(n) = A203530(n)/A000178(n-1); A000178 = (superfactorials). %C A203533 It is conjectured that every term is an integer. %t A203533 t = Table[If[PrimeQ[k], 0, k], {k, 1, 100}]; %t A203533 composite = Rest[Rest[Union[t]]] (* A002808 *) %t A203533 f[j_] := composite[[j]]; z = 20; %t A203533 v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}] %t A203533 d[n_] := Product[(i - 1)!, {i, 1, n}] (* A000178 *) %t A203533 Table[v[n], {n, 1, z}] (* A203530 *) %t A203533 Table[v[n + 1]/v[n], {n, 1, z - 1}] (* A203532 *) %t A203533 Table[v[n]/d[n], {n, 1, 20}] (* A203533 *) %Y A203533 Cf. A000178, A203530, A203532, A002808, A093883, A203420. %K A203533 nonn %O A203533 1,2 %A A203533 _Clark Kimberling_, Jan 03 2012