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A341274 Composite numbers k that are divisible by (k mod sopfr(k))+floor(k/sopfr(k)), where sopfr = A001414.

%I A341274 #11 Feb 09 2021 11:48:07
%S A341274 4,6,12,16,20,21,24,27,30,36,40,45,48,52,56,60,66,70,72,75,80,84,88,
%T A341274 90,96,105,108,112,117,126,140,150,152,160,180,182,192,195,198,200,
%U A341274 220,224,225,231,240,252,255,256,270,286,288,290,301,306,308,320,330,344,345,352,360,378,384,396,429
%N A341274 Composite numbers k that are divisible by (k mod sopfr(k))+floor(k/sopfr(k)), where sopfr = A001414.
%H A341274 Robert Israel, <a href="/A341274/b341274.txt">Table of n, a(n) for n = 1..10000</a>
%e A341274 a(5) = 20 is a term because sopfr(20) = 2*2+5 = 9, and 20 is divisible by (20 mod 9)+floor(20/9) = 4.
%p A341274 spf:= proc(n) local t; add(t[1]*t[2],t=ifactors(n)[2]) end proc:
%p A341274 filter:= proc(n) local s, m;
%p A341274   if isprime(n) then return false fi;
%p A341274   s:= spf(n);
%p A341274   m:= n mod s;
%p A341274   n mod (m + (n-m)/s) = 0
%p A341274 end proc:
%p A341274 select(filter, [$4..500]);
%Y A341274 Contains A190275.
%Y A341274 Cf. A001414.
%K A341274 nonn
%O A341274 1,1
%A A341274 _J. M. Bergot_ and _Robert Israel_, Feb 08 2021