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 A225867 a(n) = max_{2<=k<=(n-2)/2} sum_{d>1: d|n+k, k|n+d}1. 7
 3, 2, 2, 3, 4, 1, 3, 3, 4, 4, 3, 2, 4, 3, 4, 4, 6, 2, 3, 4, 4, 4, 4, 2, 5, 3, 3, 6, 6, 4, 4, 4, 6, 4, 4, 2, 4, 5, 6, 5, 8, 2, 3, 4, 4, 6, 4, 3, 6, 6, 4, 6, 8, 2, 5, 5, 6, 4, 4, 4, 6, 4, 6, 8, 9, 2, 4, 5, 4, 5, 6, 6, 8, 4, 4, 6, 8, 3, 4, 6, 6, 8, 6, 3, 5, 4, 8, 6, 10 (list; graph; refs; listen; history; text; internal format)
 OFFSET 6,1 LINKS Peter J. C. Moses, Table of n, a(n) for n = 6..10005 MAPLE A225867 := proc(n) local a, k, nd ; a := 0 ; for k from 2 to n/2-1 do nd := 0 ; for d in numtheory[divisors](n+k) minus {1} do if modp(n+d, k) = 0 then nd := nd+1; end if; end do: a := max(a, nd) ; end do: a ; end proc: # R. J. Mathar, Jul 04 2013 MATHEMATICA Table[Max[Map[Count[(n+Rest[Divisors[n+#]])/#, _Integer]&, Range[2, Floor[(n-2)/2]]]], {n, 6, 105}] (* Peter J. C. Moses, Jun 27 2013 *) PROG (PARI) a(n)=my(t); for(k=2, n\2-1, t=max(sumdiv(n+k, d, (n+d)%k==0 && d>1), t)); t \\ Charles R Greathouse IV, Nov 25 2014 CROSSREFS Sequence in context: A115061 A217834 A227877 * A046822 A129001 A029246 Adjacent sequences: A225864 A225865 A225866 * A225868 A225869 A225870 KEYWORD nonn AUTHOR Vladimir Shevelev, May 18 2013 EXTENSIONS Extended from a(14) by Peter J. C. Moses, May 18 2013 STATUS approved

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Last modified August 9 02:38 EDT 2024. Contains 375024 sequences. (Running on oeis4.)