A089925 Number of commutative loops (quasigroups with an identity element) of order n.

0, 1, 1, 1, 2, 1, 8, 17, 2265, 30583, 358335026, 69522550106, 55355570223093935, 206176045800229002160

Offset: 0

Author

Christian G. Bower and Juergen Buntrock (jubu(AT)jubu.com), Nov 14 2003

Keywords

• nonn
• hard
• more

Links

• Brendan D. McKay and Ian M. Wanless, Enumeration of Latin squares with conjugate symmetry, J. Combin. Des. 30 (2022), 105-130.
• Index entries for sequences related to quasigroups

Crossrefs

Cf. A057771, A035481, A350009, A350010, A057992.

Extensions

a(9) from Michael Thwaites (michael.thwaites(AT)ucop.edu), Jan 23 2004

a(0) prepended by Jianing Song, Oct 26 2019

a(10)-a(13) from Ian Wanless, Dec 08 2021