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%I #15 Jan 17 2020 17:39:55
%S 2,3,5,3,7,5,11,3,5,7,13,5,17,11,7,3,19,5,23,7,11,13,29,5,7,17,5,11,
%T 31,7,37,3,13,19,11,5,41,23,17,7,43,11,47,13,7,29,53,5,11,7,19,17,59,
%U 5,13,11,23,31,61,7,67,37,11,3,17,13,71,19,29,11,73,5,79,41,7,23,13,17,83,7
%N a(n) = smallest prime greater than the largest prime dividing n.
%H Reinhard Zumkeller, <a href="/A117366/b117366.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A151800(A006530(n)). - _Reinhard Zumkeller_, Apr 06 2015
%F a(n) = A000040(A159081(n)). - _Antti Karttunen_, Jan 15 2020
%e 5 is the largest prime dividing 10. So a(10) is the smallest prime > 5, which is 7.
%t Table[Prime[PrimePi[FactorInteger[n][[Length[FactorInteger[n]]]][[1]]]+1], {n, 2, 80}], 2, 1] (* _Stefan Steinerberger_, Apr 09 2006 *)
%o (Haskell)
%o a117366 = a151800 . a006530 -- _Reinhard Zumkeller_, Apr 06 2015
%o (PARI) A117366(n) = if(1==n, 2, nextprime(1+vecmax(factor(n)[, 1]))); \\ _Antti Karttunen_, Jan 15 2020
%Y Cf. A117364, A117365, A117367.
%Y Cf. A000040, A006530, A151800, A159081.
%K nonn
%O 1,1
%A _Leroy Quet_, Mar 10 2006
%E More terms from _Stefan Steinerberger_, Apr 09 2006
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