OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
rad(60) - 1 = 2*3*5 - 1 = 29, so 60 is a term.
MATHEMATICA
Select[Range[250], PrimeQ[Times @@ FactorInteger[#][[;; , 1]] - 1] &] (* Amiram Eldar, Dec 21 2022 *)
PROG
(PARI) isok(k) = isprime(factorback(factor(k)[, 1]) - 1); \\ Michel Marcus, Dec 22 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Arsen Vardanyan, Dec 21 2022
STATUS
approved