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%I #20 May 22 2024 16:56:48
%S 1,1,2,1,6,1,30,1,2,3,210,1,2310,15,2,1,30030,1,510510,3,10,105,
%T 9699690,1,6,1155,2,15,223092870,1,6469693230,1,70,15015,6,1,
%U 200560490130,255255,770,3,7420738134810,5,304250263527210,105,2,4849845
%N Product of the primes less than the greatest prime factor of n but not dividing n.
%C a(n) is squarefree, and all squarefree numbers appear infinitely often. a(m) = a(n) if and only if rad(m) = rad(n), where rad is A007947. - _Charles R Greathouse IV_, Apr 09 2024
%C Rad(n*a(n)) = A002110(A000720(A006530(n))) is the smallest primorial number divisible by rad(n). - _David James Sycamore_, May 15 2024
%H Michael De Vlieger, <a href="/A083720/b083720.txt">Table of n, a(n) for n = 1..2376</a>
%F a(n) = A002110(A049084(A006530(n)))/A007947(n).
%F a(A000040(k)) = A002110(k-1).
%F a(n) = 1 iff n = m*A002110(k) and A006530(m) <= A000040(k).
%t Array[Times @@ Complement[Prime@ Range@ PrimePi@ Last[#], #] &[FactorInteger[#][[All, 1]]] &, 46] (* _Michael De Vlieger_, Apr 09 2024 *)
%Y Cf. A079067, A083722.
%Y See the formula section for the relationships with A000040, A002110, A006530, A007947, A049084.
%K nonn,easy
%O 1,3
%A _Reinhard Zumkeller_, May 04 2003
%E Edited by _Peter Munn_, Apr 09 2024
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