OFFSET
1,1
PROG
(PARI) is(n) = my(b=precprime(precprime(precprime(n-1)-1)-1)); Mod(b, n^2)^(n-1)==1 || Mod(n, b^2)^(b-1)==1
forprime(p=7, , if(is(p), print1(p, ", ")))
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Felix Fröhlich, Sep 25 2022
STATUS
approved