OFFSET
2,2
COMMENTS
The next term has 1204 digits.
r = (n^(n-1) - 1)/(n-1) = A060072(n) is the (n-1)-digit repunit in base n.
r^2 divides n^r - 1 for all bases n > 1.
FORMULA
EXAMPLE
a(10) = (10^111111111 - 1)/111111111^2.
MATHEMATICA
Table[(n^((n^(n - 1) - 1)/(n - 1)) - 1)/((n^(n - 1) - 1)/(n - 1))^2, {n, 2, 6}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, May 04 2010
STATUS
approved