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%I #13 Oct 19 2016 03:05:12
%S 1,2,1,2,1,4,3,2,1,2,1,2,5,2,1,2,1,4,3,2,1,6,1,2,3,2,1,2,1,4,3,2,7,2,
%T 1,2,3,2,1,2,1,4,3,2,1,8,1,2,3,2,1,6,5,4,3,2,1,2,1,2,9,4,5,2,1,4,3,2,
%U 1,2,1,2,5,2,7,2,1,10,3,2,1,6,1,2,3,2,1,6,1,4,3,2,5,2,1,2,11,2
%N a(n) = the largest proper divisor k of n where (k-1) and/or (k+1) divides (n+1).
%H G. C. Greubel, <a href="/A135545/b135545.txt">Table of n, a(n) for n = 3..1000</a>
%e 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.
%t 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 *)
%K nonn
%O 3,2
%A _Leroy Quet_, May 10 2008
%E More terms from _Stefan Steinerberger_, Aug 30 2008
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