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%I #20 May 11 2020 05:45:51
%S 1,2,3,1,15,6,105,6,35,60,385,90,5005,1260,75075,315,1276275,210,
%T 24249225,525,509233725,11550,11712375675,34650,2342475135,900900,
%U 2342475135,3153150,67931778915,28028,2105885146365,14014,2573859623335
%N Cubefree part of n!!.
%H Chai Wah Wu, <a href="/A145643/b145643.txt">Table of n, a(n) for n = 1..500</a>
%F a(n) = A050985(A006882(n)). - _Michel Marcus_, May 11 2020
%t CubefreePart[n_Integer?Positive] := Times @@ Power @@@ ({#[[1]], Mod[ #[[2]], 3]} & /@ FactorInteger[n]); Table[CubefreePart[n!! ], {n, 1, 40}]
%o (Python)
%o from sympy import factorint, prod
%o def A145643(n):
%o return 1 if n <= 1 else prod(p**(e % 3) for p, e in factorint(prod(range(n,0,-2))).items())
%o # _Chai Wah Wu_, Feb 04 2015
%Y Cf. A004709, A050985, A006882, A069705 (cubefree part of 2^n), A145642.
%K nonn
%O 1,2
%A _Artur Jasinski_, Oct 15 2008
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