OFFSET
3,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 3..1000
EXAMPLE
The proper divisors of 14 are 1,2,7. Now 2 is the largest of these divisors k where (k-1) and/or (k+1) divides 15 -- both (2-1) and (2+1) divide 15. So a(14) = 2.
MATHEMATICA
Table[Max[Join[{1}, Select[Complement[Divisors[n], {1, n}], Mod[n + 1, # + 1] == 0 || Mod[n + 1, # - 1] == 0 &]]], {n, 3, 100}] (* Stefan Steinerberger, Aug 30 2008 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, May 10 2008
EXTENSIONS
More terms from Stefan Steinerberger, Aug 30 2008
STATUS
approved