OFFSET
1,1
COMMENTS
If in the definition "greatest" is replaced with "smallest", then we obtain A035095 (see comment there).
FORMULA
a(n) == 1 (mod prime(n)).
PROG
(PARI) a(n) = {mini = 0; p = prime(n); for (i=2, p, f = factor((i^p-1)/(i-1)); gpf = f[#f~, 1]; if (! mini, mini = gpf, mini = min(mini, gpf)); ); mini; } \\ Michel Marcus, Dec 09 2014
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vladimir Shevelev, Nov 27 2014
EXTENSIONS
More terms from Peter J. C. Moses, Nov 27 2014
a(13)-a(14) from Michel Marcus, Dec 09 2014
a(15)-a(16) from Jinyuan Wang, Mar 03 2020
STATUS
approved