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%I #16 Jun 19 2018 03:16:16
%S 2,3,3,5,4,7,5,5,6,11,6,13,8,7,9,17,8,19,8,9,12,23,10,9,14,11,10,29,
%T 10,31,17,13,18,11,14,37,20,15,12,41,12,43,14,13,24,47,18,13,14,19,16,
%U 53,20,15,14,21,30,59,16,61,32,15,33,17,16,67,20,25,16,71,26,73,38,19,22
%N a(n) = n/gpf(n) + gpf(n) - 1, where gpf = A006530 = greatest prime factor.
%C a(n) = A052126(n) + A006530(n) - 1; a(n) <= n and for n > 1: a(n) = n iff n is prime.
%H Harry J. Smith, <a href="/A064920/b064920.txt">Table of n, a(n) for n = 2..1000</a>
%e a(18) = 18/2 + 2 - 1 = 10;
%e a(19) = 19/19 + 19 - 1 = 19.
%t a[n_] := (g = FactorInteger[n][[-1, 1]]; n/g + g - 1); a /@ Range[2, 76] (* _Jean-François Alcover_, Apr 06 2011 *)
%o (PARI) gpf(n)= { local(f); f=factor(n)~; return(f[1, length(f)]) } { for (n=2, 1000, g=gpf(n); a=n / g + g - 1; write("b064920.txt", n, " ", a) ) } \\ _Harry J. Smith_, Sep 29 2009
%o (PARI) a(n) = my(p = vecmax(factor(n)[,1])); n/p + p - 1; \\ _Michel Marcus_, Jun 19 2018
%Y Cf. A064916, A064921, A064922, A006530, A052126, A064923, A064924.
%K nice,nonn
%O 2,1
%A _Reinhard Zumkeller_, Oct 14 2001
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