A140189 Number of groupoids (categories all of whose morphisms are invertible) with n morphisms.

1, 1, 2, 3, 7, 9, 16, 22, 42, 57, 90, 124, 204, 275, 413, 562, 866, 1161, 1685, 2264, 3308, 4407

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: A075855 A347268 A360251 * A327066 A165803 A378925

Adjacent sequences: A140186 A140187 A140188 * A140190 A140191 A140192

Keyword

nonn

Author

Benoit Jubin, May 12 2008

Status

approved