login
A116034
Numbers k such that phi(k) + prime(k) is a prime.
2
1, 3, 7, 8, 9, 11, 12, 13, 16, 18, 20, 22, 24, 26, 29, 31, 33, 35, 36, 37, 38, 39, 42, 43, 47, 48, 49, 52, 53, 54, 66, 67, 70, 72, 73, 74, 75, 76, 77, 78, 79, 82, 84, 85, 90, 92, 93, 95, 98, 101, 104, 105, 110, 112, 115, 120, 122, 123, 124, 129, 133, 134, 140, 145
OFFSET
1,2
LINKS
EXAMPLE
phi(145) + prime(145) = 941 (a prime).
MAPLE
select(k -> isprime(numtheory:-phi(k) + ithprime(k)), [$1..1000]); # Robert Israel, Aug 18 2024
MATHEMATICA
Select[Range[145], PrimeQ[EulerPhi[#]+Prime[#]]&] (* James C. McMahon, Sep 27 2024 *)
CROSSREFS
Cf. A116033.
Sequence in context: A328980 A059101 A091679 * A364166 A122987 A047530
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved