A079192 Number of non-associative non-commutative closed binary operations on a set of order n.

0, 0, 6, 18904, 4293916368, 298023193359221998, 10314424798468598595515695154, 256923577521058877628624940679487983651948, 6277101735386680763835789098689112757675628513119817261598

Offset: 0

Author

Christian van den Bosch (cjb(AT)cjb.ie), Jan 03 2003

Keywords

• nonn

Links

• C. van den Bosch, Closed binary operations on small sets
• Index entries for sequences related to groupoids

Crossrefs

Cf. A002489, A023813, A023814, A023815, A079193 (isomorphism classes), A079194, A079195, A079198.

Formula

a(n) + A079195(n) + A079198(n) + A023815(n) = A002489(n).

a(n) = Sum_{k>=1} A079194(n,k)*A079210(n,k).

a(n) = A002489(n) - A023813(n) - A023814(n) + A023815(n). - Andrew Howroyd, Jan 26 2022

Extensions

a(0)=0 prepended and a(5)-a(8) added by Andrew Howroyd, Jan 26 2022