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

0,5

Links

Table of n, a(n) for n=0..13.

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.

Sequence in context: A121360 A199928 A047688 * A235047 A120945 A235048

Adjacent sequences: A089922 A089923 A089924 * A089926 A089927 A089928

Keyword

nonn,hard,more

Author

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

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

Status

approved