%I #12 Dec 29 2023 21:33:18

%S 2,3,7,13,43,41,157,109,193,313,487,337,241,661,433,937,641,881,1013,

%T 769,1249,2053,1861,2269,3121,1321,4423,3037,3001,4621,1873,6163,2017,

%U 5441,3613,2161,6553,4049,5581

%N Primes of the form n*phi(n)+1 where phi(n) is the Euler function.

%C Listed in order of increasing n.

%H T. D. Noe, <a href="/A046062/b046062.txt">Table of n, a(n) for n=1..1000</a>

%e 7 because 3*phi(3)+1 = 7 is prime.

%t Select[Array[# EulerPhi[#]+1&,500],PrimeQ] (* _Harvey P. Dale_, Apr 21 2012 *)

%Y Cf. A002618, A046078.

%K easy,nice,nonn

%O 1,1

%A _Felice Russo_