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Partial products of A029940 (Product_{d|n} phi(d)).
2

%I #13 Sep 08 2024 19:25:33

%S 1,1,2,4,16,64,384,3072,36864,589824,5898240,188743680,2264924160,

%T 81537269760,5218385264640,333976656936960,5343626510991360,

%U 769482217582755840,13850679916489605120,3545774058621338910720,510591464441472803143680,51059146444147280314368000

%N Partial products of A029940 (Product_{d|n} phi(d)).

%C phi(n) is the number of totatives of n (A000010).

%F a(n) = Product_{i=1..n} A029940(i).

%t FoldList[Times[#1, #2] &, Array[Product[EulerPhi@ d, {d, Divisors@ #}] &, 22]] (* _Michael De Vlieger_, Dec 27 2016 *)

%o (Magma) [&*[&*[EulerPhi(d): d in Divisors(k)]: k in [1..n]]: n in [1..100]];

%Y Cf. A000010, A029940, A280131 (partial sums of A029940), A280133 (partial products of A057661).

%K nonn

%O 1,3

%A _Jaroslav Krizek_, Dec 27 2016