A048848 a(n) = prime(phi(n)).

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, 61, 37, 107, 19, 113, 53, 71, 53, 89, 37, 151, 61, 89, 53, 173, 37, 181, 71, 89, 79, 199, 53, 181, 71, 131, 89, 239, 61, 173, 89, 151, 107, 271, 53, 281

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000010, A000040, A048849.

Programs

Magma

[NthPrime(EulerPhi(n)): n in [1..100]]; // G. C. Greubel, Feb 22 2024

Maple

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

Mathematica

Prime[EulerPhi[Range[70]]] (* Harvey P. Dale, Nov 24 2022 *)

PARI

A048848(n) = prime(eulerphi(n)); \\ Antti Karttunen, Dec 05 2017

SageMath

[nth_prime(euler_phi(n)) for n in range(1,101)] # G. C. Greubel, Feb 22 2024

Formula

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

Extensions

Offset corrected by Antti Karttunen, Dec 05 2017