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A083716 a(n) = integer part of (greatest prime <= n)/(greatest prime factor of n); a(1) = 1. 5

%I #17 Mar 04 2019 18:53:02

%S 1,1,1,1,1,1,1,3,2,1,1,3,1,1,2,6,1,5,1,3,2,1,1,7,4,1,7,3,1,5,1,15,2,1,

%T 4,10,1,1,2,7,1,5,1,3,8,1,1,15,6,9,2,3,1,17,4,7,2,1,1,11,1,1,8,30,4,5,

%U 1,3,2,9,1,23,1,1,14,3,6,5,1,15,26,1,1,11,4,1,2,7,1,17,6,3,2,1,4,29,1,13,8

%N a(n) = integer part of (greatest prime <= n)/(greatest prime factor of n); a(1) = 1.

%C a(n) = floor(A007917(n)/A006530(n));

%C a(p) = 1 for primes p.

%H Robert Israel, <a href="/A083716/b083716.txt">Table of n, a(n) for n = 1..10000</a>

%p 1,seq(floor(prevprime(n+1)/max(numtheory:-factorset(n))), n=2..100); # _Robert Israel_, Jun 13 2017

%t a[n_] := If[n == 1 || PrimeQ[n], 1, Floor[NextPrime[n, -1]/ FactorInteger[n][[-1, 1]]]];

%t Array[a, 100] (* _Jean-François Alcover_, Mar 04 2019 *)

%Y Cf. A006530, A007917.

%Y Cf. A083715, A083717, A083714, A083718.

%K nonn,look

%O 1,8

%A _Reinhard Zumkeller_, May 04 2003

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Last modified August 27 09:19 EDT 2024. Contains 375468 sequences. (Running on oeis4.)