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A382468 a(n) = (largest prime factor of n) minus (its remaining distinct prime factors).

%I A382468 #20 Apr 01 2025 05:43:50
%S A382468 2,3,2,5,1,7,2,3,3,11,1,13,5,2,2,17,1,19,3,4,9,23,1,5,11,3,5,29,0,31,
%T A382468 2,8,15,2,1,37,17,10,3,41,2,43,9,2,21,47,1,7,3,14,11,53,1,6,5,16,27,
%U A382468 59,0,61,29,4,2,8,6,67,15,20,0,71,1,73,35,2,17,4,8,79,3,3
%N A382468 a(n) = (largest prime factor of n) minus (its remaining distinct prime factors).
%H A382468 Paolo Xausa, <a href="/A382468/b382468.txt">Table of n, a(n) for n = 2..10000</a>
%F A382468 a(p) = p, for p prime.
%F A382468 a(n) = 2*A006530(n) - A008472(n).
%p A382468 A382468 := proc(n)
%p A382468     2*A006530(n)-A008472(n) ;
%p A382468 end proc:
%p A382468 seq( A382468(n),n=1..50) ; # _R. J. Mathar_, Apr 01 2025
%t A382468 A382468[n_] := Last[#] - Total[Most[#]] & [FactorInteger[n][[All, 1]]];
%t A382468 Array[A382468, 100, 2]
%Y A382468 Cf. A212665 (positions of negative terms), A215142 (positions of ones), A382469 (positions of zeros).
%Y A382468 Cf. A006530, A008472, A027748.
%K A382468 sign,easy
%O A382468 2,1
%A A382468 _Paolo Xausa_, Mar 31 2025