OFFSET
1,2
COMMENTS
For n >= 2, a(n) is odd and squarefree. - Robert Israel, Jul 29 2016
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
5 is a term because A000010(5) + 5^2 = 29 is a prime number.
MAPLE
select(t -> isprime(numtheory:-phi(t) + t^2), [1, 2, seq(n, n=3..1000, 2)]); # Robert Israel, Jul 29 2016
MATHEMATICA
Select[Range[2000], PrimeQ[#^2 + EulerPhi[#]] &]
PROG
(Magma) [n: n in [1..800] | IsPrime(n^2+EulerPhi(n))];
(PARI) isok(n) = isprime(eulerphi(n) + n^2); \\ Altug Alkan, Jul 27 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jul 27 2016
STATUS
approved