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A125696 Number of categories with n morphisms. 5
1, 3, 11, 55, 329, 2858 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

LINKS

Eric Weisstein's World of Mathematics, Category

FORMULA

Euler transform of A125698. G.f. Product_{i=1}^{infinity} 1/(1-x^i)^A125698(i).

EXAMPLE

The 11 categories with 3 morphisms consist of 7 3-element disconnected combinations of a 2-element monoid and a 1 element monoid, 1 with 3 separate 1-element monoids and one 2-object category with a single morphism between the objects.

CROSSREFS

Cf. A058129, A125697, A125698, A125720.

Sequence in context: A094259 A091845 A020061 * A001776 A180875 A136104

Adjacent sequences:  A125693 A125694 A125695 * A125697 A125698 A125699

KEYWORD

hard,more,nonn

AUTHOR

Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net) and Christian Bower (bowerc(AT)usa.net), Jan 05 2007

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Last modified February 17 08:44 EST 2012. Contains 205998 sequences.