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 A281019 Partial products of A051953; a(1) = 1. 1

%I

%S 1,1,1,2,2,8,8,32,96,576,576,4608,4608,36864,258048,2064384,2064384,

%T 24772608,24772608,297271296,2675441664,32105299968,32105299968,

%U 513684799488,2568423997440,35957935964160,323621423677440,5177942778839040,5177942778839040

%N Partial products of A051953; a(1) = 1.

%H Indranil Ghosh, <a href="/A281019/b281019.txt">Table of n, a(n) for n = 1..505</a>

%F a(1) = 1; for n>1, a(n) = Product_{i=2..n} A051953(i).

%t Table[If[n==1, 1, Product[i - EulerPhi[i], {i, 2, n}]], {n, 1, 29}] (* _Indranil Ghosh_, Mar 09 2017 *)

%o (MAGMA) [1] cat [&*[#[h: h in [2..k] | GCD(h,k) ne 1]: k in [2..n]]: n in [2..100]]

%o (PARI) for (n=1, 29, print1(if(n==1, 1, prod(i=2, n, i - eulerphi(i))),", ")); \\ _Indranil Ghosh_, Mar 09 2017

%Y Cf. A051953(n) = number of cototatives of n.

%Y Cf. A063985.

%K nonn

%O 1,4

%A _Jaroslav Krizek_, Jan 13 2017

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Last modified November 28 00:12 EST 2021. Contains 349395 sequences. (Running on oeis4.)