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A140189 Number of groupoids (categories all of whose morphisms are invertible) with n morphisms. 2
1, 1, 2, 3, 7, 9, 16, 22, 42, 57, 90, 124, 204, 275, 413, 562, 866, 1161, 1685, 2264, 3308, 4407 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Row sums of A140188 (see comments and formula there).

LINKS

Table of n, a(n) for n=0..21.

CROSSREFS

Cf. A140185, A140188.

Sequence in context: A109660 A236544 A075855 * A327066 A165803 A327779

Adjacent sequences:  A140186 A140187 A140188 * A140190 A140191 A140192

KEYWORD

nonn

AUTHOR

Benoit Jubin, May 12 2008

STATUS

approved

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Last modified October 23 22:58 EDT 2019. Contains 328379 sequences. (Running on oeis4.)