%I A064372
%S A064372 1,1,1,1,1,2,1,1,1,2,1,2,1,2,2,1,1,2,1,2,2,2,1,2,1,2,1,2,1,3,1,1,2,2,2,
%T A064372 2,1,2,2,2,1,3,1,2,2,2,1,2,1,2,2,2,1,2,2,2,2,2,1,3,1,2,2,2,2,3,1,2,2,3,
%U A064372 1,2,1,2,2,2,2,3,1,2,1,2,1,3,2,2,2,2,1,3,2,2,2,2,2,2,1,2,2,2,1,3,1,2,3
%N A064372 Additive function a(n) defined by the recursive formula a(1)=1 and a(p^k)=a(k) 
               for any prime p.
%C A064372 That is, if i, j, k, ... are relatively prime, then a(i*j*k*...) = a(i)+a(j)+a(k)+... 
               - N. J. A. Sloane (njas(AT)research.att.com), Nov 20 2007
%C A064372 Starts almost the same as A001221 (the number of distinct primes dividing 
               n): the first twelve terms which are different are a(1), a(64), a(192), 
               a(320), a(448), a(576), a(704), a(729), a(832), a(960), a(1024) and 
               a(1088), since the first non-unitary values of n are a(6) and(10). 
               - Henry Bottomley (se16(AT)btinternet.com), Sep 23 2002
%H A064372 T. D. Noe, <a href="b064372.txt">Table of n, a(n) for n=1..10000</a>
%F A064372 a(n) = A106491(n)-A106490(n) = A106495(A106444(n)). - Antti Karttunen 
               (Antti.Karttunen(AT)gmail.com), May 09 2005
%e A064372 a(30) = a(5^1 * 3^1 * 2^1) = a(1)+a(1)+a(1) = 3.
%Y A064372 Cf. A001221, A079553.
%Y A064372 Sequence in context: A087802 A079553 A001221 this_sequence A096825 A007875 
               A050320
%Y A064372 Adjacent sequences: A064369 A064370 A064371 this_sequence A064373 A064374 
               A064375
%K A064372 nonn,easy,nice
%O A064372 1,6
%A A064372 S. R. Finch (Steven.Finch(AT)inria.fr), Sep 26 2001