A079182 Number of non-commutative closed binary operations on a set of order n.

0, 8, 18954, 4293918720, 298023193359375000, 10314424798468598595531571200, 256923577521058877628624940679495660344806, 6277101735386680763835789098689112757675628661308013936640

Offset: 1

Author

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

Keywords

• nonn

Comments

A023813(n) + A079182(n) = A002489(n).

Each a(n) is equal to the sum of the products of each element in row n of A079184 and the corresponding element of A079210.

Links

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

Crossrefs

Cf. A023813, A079178, A079180.

Programs

Mathematica

Table[n^(n^2)-n^((n^2+n)/2), {n,1,10}] (* Geoffrey Critzer, Jan 27 2013 *)

Formula

a(n) = n^(n^2)-n^((n^2-n)/2).

Extensions

More terms from Geoffrey Critzer, Jan 27 2013