%I #15 Dec 31 2015 16:23:15
%S 2145,2730,4641,4845,5005,5610,7410,8778,9177,11305,11730,13485,13585,
%T 17017,20010,20930,21489,21505,23529,26445,29946,31465,31857,32538,
%U 33649,34410,35409,35581,36685,38570,38874,41106,42441,43401,45066,46189,46345,47730,49569
%N Primitive (squarefree) elements of A199745.
%H Robert Israel, <a href="/A200145/b200145.txt">Table of n, a(n) for n = 1..10000</a>
%p Filter:= proc(n) local F;
%p F:= ifactors(n)[2];
%p if max(seq(f[2],f=F)) > 1 or nops(F) < 4 then return false fi;
%p F:= map(t -> t[1],F);
%p convert(F,`+`) = 2*(max(F)+min(F));
%p end proc:
%p select(Filter,[$1..10^5]); # _Robert Israel_, Dec 31 2015
%t Select[Range[50000],Max@@Last/@(fi=FactorInteger[#])==1&&Plus@@(pl=First/@fi)/2==pl[[1]]+pl[[-1]]&] (*Ray Chandler, Nov 14 2011*)
%Y Intersection of A199745 and A005117.
%K nonn
%O 1,1
%A _Ray Chandler_, Nov 14 2011