OFFSET
2,1
PROG
(PARI) for(n=2, 20, i=0; forcomposite(c=2, 1e9, if(Mod(n, c)^(c-1)==1, i++; if(i==n, print1(c, ", "); i=0; break({1}))); if(c==1e9, print1(">1e9, "))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Sep 26 2014
STATUS
approved