OFFSET
1,1
COMMENTS
For these terms, mu(phi(p)) must be zero.
For prime p, phi(p) = p-1, so terms are primes p such that 2p-1 is also prime (A005382) and p-1 is not squarefree. - Jens Kruse Andersen, Jul 19 2014
LINKS
Jens Kruse Andersen, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1)=19 as 19+18+0 is prime.
a(2)=37 as 37+36+0 is prime.
a(3)=97 as 97+96+0 is prime.
MAPLE
with(numtheory): A244111:=n->`if`(isprime(n+phi(n)+mobius(phi(n))) and isprime(n), n, NULL); seq(A244111(n), n=1..5000); # Wesley Ivan Hurt, Jul 19 2014
MATHEMATICA
apQ[n_]:=Module[{p=EulerPhi[n]}, PrimeQ[n+p+MoebiusMu[p]]]; Select[Prime[ Range[500]], apQ] (* Harvey P. Dale, Jun 13 2015 *)
PROG
(PARI) isok(n) = isprime(n) && isprime(n + eulerphi(n) + moebius(eulerphi(n))); \\ Michel Marcus, Jun 21 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Torlach Rush, Jun 20 2014
EXTENSIONS
More terms from Michel Marcus, Jun 21 2014
STATUS
approved