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 A281027 #13 Aug 16 2025 09:35:07
%S A281027 1,2,6,48,240,34560,241920,92897280,15049359360,288947699712000,
%T A281027 3178424696832000,3954468870810501120000,51408095320536514560000,
%U A281027 232150733172291613910630400000,338475768965201173081699123200000000,3493719809197289292455451813740544000000000
%N A281027 Partial products of A066570.
%F A281027 a(n) = Product_{i=1..n} A066570(i).
%F A281027 a(n) = A000178(n)/A280821(n). - _Amiram Eldar_, Aug 16 2025
%t A281027 FoldList[Times, Table[Times @@ Select[Range[2, n], ! CoprimeQ[n, #] &], {n, 1, 16}]] (* _Amiram Eldar_, Aug 16 2025 *)
%o A281027 (Magma) [1] cat [&*[&*[h: h in [2..k] | GCD(h,k) ne 1]: k in [2..n]]: n in [2..100]];
%Y A281027 Cf. A066570(n) = the product of cototatives of n.
%Y A281027 Cf. A000178, A280821, A281025.
%K A281027 nonn
%O A281027 1,2
%A A281027 _Jaroslav Krizek_, Jan 19 2017