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Number of isomorphism abelian groups of order 2000?

$2000 = 2^4 5^3$, and the non-isomorphic groups is just $4\times 3$.

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    The key word here is *partition*. See http://mathworld.wolfram.com/AbelianGroup.html2011-04-27
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    http://en.wikipedia.org/wiki/Fundamental_theorem_of_finitely_generated_abelian_groups#Classification2011-04-27
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    @Qiaochu, unfortunately that Wikipedia page does not mention the number of isomorphism classes; it does not even mention partitions. Hence my link to MathWorld. I'd edit the Wikipedia page, but I couldn't find a nice place to add something on the number of isomorphism classes. (Ok, I didn't look too hard.)2011-04-27

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