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 A280133 #7 Sep 08 2022 08:46:18
%S A280133 1,2,8,48,528,5808,127776,2811072,87143232,2788583424,156160671744,
%T A280133 6090266198016,481131029643264,31273516926812160,2314240252584099840,
%U A280133 199024661722232586240,27266378655945864314880,2508506836347019516968960,431463175851687356918661120
%N A280133 Partial products of A057661 (Sum_{d|n} psi(d)).
%C A280133 psi(n) is the sum of the totatives of n (A023896).
%F A280133 a(n) = Product_{i=1..n} A057661(i).
%t A280133 FoldList[Times[#1, #2] &, Array[Sum[Total@ Select[Range@ d, CoprimeQ[#, d] &], {d, Divisors@ #}] &, 19]] (* _Michael De Vlieger_, Dec 27 2016 *)
%o A280133 (Magma) [&*[&+[&+[h: h in [1..d] | GCD(h,d) eq 1]: d in Divisors(k)]: k in [1..n]]: n in [1..1000]]
%Y A280133 Cf. A000010, A057661, A232533 (partial sums of A057661), A280132 (partial products of A029940).
%K A280133 nonn
%O A280133 1,2
%A A280133 _Jaroslav Krizek_, Dec 27 2016