OFFSET
1
COMMENTS
LINKS
Felix Fröhlich, Table of n, a(n) for n = 1..10000
EXAMPLE
The largest k such that c = 133, i.e. A002808(100), satisfies the congruence b^(c-1) == 1 (mod c^k) for 1 < b < 133 is 2, which happens for b = 68. Since there is no other b with 1 < b < c and c satisfying this congruence for a larger k, a(100) = 2.
PROG
(PARI) forcomposite(c=1, 1e2, my(maxexp=0, k=1); for(b=2, c-1, while(Mod(b, c^k)^(c-1)==1, k++); if(k-1 > maxexp, maxexp=k-1)); print1(maxexp, ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Jan 31 2016
STATUS
approved