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%I A104354 #21 Apr 08 2024 01:38:30
%S A104354 1,1,2,4,16,48,288,576,1728,8640,86400,259200,3110400,21772800,
%T A104354 108864000,217728000,3483648000,10450944000,188116992000,940584960000,
%U A104354 6584094720000,72425041920000,1593350922240000,4780052766720000,23900263833600000,310703429836800000
%N A104354 Euler's totient of A104350(n).
%H A104354 Amiram Eldar, Table of n, a(n) for n = 1..640
%H A104354 Reinhard Zumkeller, Products of largest prime factors of numbers <= n.
%F A104354 a(n) = A000010(A104350(n)).
%t A104354 EulerPhi[FoldList[Times, Array[FactorInteger[#][[-1, 1]] &, 30]]] (* _Amiram Eldar_, Apr 08 2024 *)
%o A104354 (PARI) gpf(n) = my(f=factor(n)[, 1]); f[#f];
%o A104354 a(n) = eulerphi(prod(i=2, n, gpf(i))); \\ _Michel Marcus_, Nov 12 2023
%Y A104354 Cf. A000010, A048855, A104350.
%K A104354 nonn
%O A104354 1,3
%A A104354 _Reinhard Zumkeller_, Mar 06 2005
%E A104354 a(1) prepended by _Michel Marcus_, Nov 12 2023
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