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a(n) = prime(phi(n)).
3

%I #15 Feb 22 2024 20:21:42

%S 2,2,3,3,7,3,13,7,13,7,29,7,37,13,19,19,53,13,61,19,37,29,79,19,71,37,

%T 61,37,107,19,113,53,71,53,89,37,151,61,89,53,173,37,181,71,89,79,199,

%U 53,181,71,131,89,239,61,173,89,151,107,271,53,281

%N a(n) = prime(phi(n)).

%H Antti Karttunen, <a href="/A048848/b048848.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A000040(A000010(n)).

%p with(numtheory); [ seq(ithprime(phi(i)),i=1..80) ];

%t Prime[EulerPhi[Range[70]]] (* _Harvey P. Dale_, Nov 24 2022 *)

%o (PARI) A048848(n) = prime(eulerphi(n)); \\ _Antti Karttunen_, Dec 05 2017

%o (Magma) [NthPrime(EulerPhi(n)): n in [1..100]]; // _G. C. Greubel_, Feb 22 2024

%o (SageMath) [nth_prime(euler_phi(n)) for n in range(1,101)] # _G. C. Greubel_, Feb 22 2024

%Y Cf. A000010, A000040, A048849.

%K nonn

%O 1,1

%A _N. J. A. Sloane_

%E Offset corrected by _Antti Karttunen_, Dec 05 2017