A209412 Number of nonisomorphic semigroups of order 2^n.

1, 5, 188, 3684030417

Offset: 0

Author

Jonathan Vos Post, Mar 08 2012

Keywords

• nonn
• hard

Comments

This is to A000679 as semigroups are to groups.

Examples

			a(3) = 3684030417 because there are 3684030417 nonisomorphic semigroups of order 2^3 = 8.
		

Crossrefs

Cf. A000079, A000679 Number of groups of order 2^n, A027851 Number of nonisomorphic semigroups of order n.

Formula

a(n) = A027851(A000079(n)).