A209412 Number of nonisomorphic semigroups of order 2^n.

1, 5, 188, 3684030417

Offset

0,2

Comments

This is to A000679 as semigroups are to groups.

Links

Table of n, a(n) for n=0..3.

Formula

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

Example

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.

Sequence in context: A208410 A268001 A096543 * A353879 A138733 A222363

Adjacent sequences: A209409 A209410 A209411 * A209413 A209414 A209415

Keyword

nonn,hard

Author

Jonathan Vos Post, Mar 08 2012

Status

approved