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%I #14 Oct 26 2019 16:29:31
%S 3,2,3,3,5,7,3,5,11,7,5,19,7,11,23,13,29,31,17,7,37,13,41,11,7,17,17,
%T 53,11,19,7,13,23,23,37,19,79,41,83,43,89,13,19,97,11,11,53,37,113,23,
%U 29,17,11,7,43,131,67,17,139,47,71,73,17,31,157,79,83,13,173,29,59
%N Greatest prime factor of the product of the neighbors of the n-th prime.
%C a(n) = A006530((A000040(n)-1)*(A000040(n)+1)) = A006530(A006093(n)*A008864(n)) = A006530(A084920(n)).
%C Apparently a(n) = A024710(n) for n>4. - _Georg Fischer_, Oct 06 2018
%H Reinhard Zumkeller, <a href="/A087713/b087713.txt">Table of n, a(n) for n = 1..10000</a>
%e a(10) = A006530(A000040(10)^2 - 1) = A006530(29*29-1) =
%e A006530(840) = A006530(7*5*3*2^3) = 7.
%t FactorInteger[#][[-1,1]]&/@((#-1)(#+1)&/@Prime[Range[80]]) (* _Harvey P. Dale_, Oct 26 2019 *)
%o (Haskell)
%o a087713 = a006530 . a084920 -- _Reinhard Zumkeller_, Aug 27 2013
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Sep 28 2003
%E Definition clarified by _Harvey P. Dale_, Oct 26 2019
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