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A280169 Expansion of Product_{k>=2} 1/(1 - mu(2*k-1)^2*x^(2*k-1)), where mu() is the Moebius function (A008683). 1

%I #4 Dec 27 2016 23:22:27

%S 1,0,0,1,0,1,1,1,1,1,2,2,2,3,3,4,4,5,6,6,8,9,10,11,13,14,17,18,21,24,

%T 26,30,33,38,42,47,53,58,65,73,80,90,99,110,122,134,149,164,181,199,

%U 220,242,266,292,321,352,386,424,463,507,554,606,662,722,788,860,936,1020,1111,1208,1314,1428,1553,1685,1829,1984,2152

%N Expansion of Product_{k>=2} 1/(1 - mu(2*k-1)^2*x^(2*k-1)), where mu() is the Moebius function (A008683).

%C Number of partitions of n into odd squarefree parts > 1.

%H Joerg Arndt, <a href="http://www.jjj.de/fxt/#fxtbook">Matters Computational (The Fxtbook)</a>, section 16.4.3 "Partitions into square-free parts", pp.351-352

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Squarefree.html">Squarefree</a>

%H <a href="/index/Par#partN">Index entries for related partition-counting sequences</a>

%F G.f.: Product_{k>=2} 1/(1 - mu(2*k-1)^2*x^(2*k-1)).

%e a(13) = 3 because we have [13], [7, 3, 3] and [5, 5, 3].

%t nmax = 76; CoefficientList[Series[Product[1/(1 - MoebiusMu[2 k - 1]^2 x^(2 k - 1)), {k, 2, nmax}], {x, 0, nmax}], x]

%Y Cf. A005117, A008683, A056911, A073576, A134345, A144338, A280127.

%K nonn

%O 0,11

%A _Ilya Gutkovskiy_, Dec 27 2016

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