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n-[n/m], where m is the least nondivisor of n (as in A007978) and [ ] = floor.
3

%I #12 Oct 10 2016 02:44:50

%S 1,2,2,3,3,5,4,6,5,7,6,10,7,10,8,11,9,14,10,14,11,15,12,20,13,18,14,

%T 19,15,23,16,22,17,23,18,29,19,26,20,27,21,32,22,30,23,31,24,39,25,34,

%U 26,35,27,41,28,38,29,39,30,52,31,42,32,43,33,50,34,46,35,47,36

%N n-[n/m], where m is the least nondivisor of n (as in A007978) and [ ] = floor.

%C If n is odd, a(n) = (n+1)/2. - _Robert Israel_, Oct 09 2016

%H Robert Israel, <a href="/A213634/b213634.txt">Table of n, a(n) for n = 1..10000</a>

%e a(10) = 10 - [10/3] = 7.

%p f:= proc(n) local m;

%p for m from 2 do if n mod m <> 0 then return n - iquo(n,m) fi od

%p end proc:

%p map(f, [$1..100]); # _Robert Israel_, Oct 09 2016

%t (See A213633.)

%Y Cf. A007978, A213633.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Jun 16 2012