OFFSET
1,1
COMMENTS
Numbers n such that A255920(n) = 9.
PROG
(PARI) is(n) = my(i=0); forprime(p=1, n-1, if(Mod(n, p^2)^(p-1)==1, i++)); i==9
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, May 26 2019
STATUS
approved