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A125696
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Number of categories with n morphisms.
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5
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OFFSET
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0,3
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LINKS
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Eric Weisstein's World of Mathematics, Category
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FORMULA
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G.f.: Product_{i>=1} 1/(1-x^i)^A125698(i).
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EXAMPLE
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The 11 categories with 3 morphisms consist of:
* 7=A058129(3) categories with 1 object (monoids),
* 3 categories with 2 objects, consisting of: 2=A058129(2) disconnected combinations of a 2-element monoid and a 1-element monoid, and the category with 2 objects and a single morphism between the two objects,
* 1 category with 3 objects (3 separate 1-element monoids).
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CROSSREFS
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KEYWORD
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hard,more,nonn
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AUTHOR
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EXTENSIONS
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a(0) and a(7)-a(9) from Thomas Anton, from the work of G. Cruttwell and R. Leblanc, Jan 25 2019
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STATUS
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approved
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