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Euler totient function of the factorial of prime(n).
2

%I #17 Jun 03 2024 03:47:48

%S 1,2,32,1152,8294400,1194393600,64210599936000,20804234379264000,

%T 4229084764616785920000,1396531754239566739931136000000,

%U 1256878578815610065938022400000000,2046959290878571310305421983481856000000000,4853749870531268290996216607232176947200000000000

%N Euler totient function of the factorial of prime(n).

%H Amiram Eldar, <a href="/A055929/b055929.txt">Table of n, a(n) for n = 1..87</a>

%F a(n) = phi(prime(n)!) = A000010(A039716(n)) = A048855(prime(n)).

%t a[n_] := EulerPhi[Prime[n]!]; Array[a, 12] (* _Amiram Eldar_, Jun 03 2024 *)

%o (PARI) a(n) = eulerphi(prime(n)!); \\ _Amiram Eldar_, Jun 03 2024

%Y Cf. A000010, A000142, A039716, A048855.

%K nonn

%O 1,2

%A _Labos Elemer_, Jul 17 2000

%E a(12)-a(13) from _Amiram Eldar_, Jun 03 2024