A057997 Number of labeled loops (quasigroups with an identity element).

1, 2, 3, 16, 280, 56448, 118594560, 4282251214848, 3398378138678329344, 75807214831601328114892800

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Index entries for sequences related to quasigroups

Crossrefs

a(n)=A000315(n)*n. Cf. A057771.

Sequence in context: A179442 A299424 A215638 * A290590 A263802 A005273

Adjacent sequences: A057994 A057995 A057996 * A057998 A057999 A058000

Keyword

nonn,hard

Author

Christian G. Bower, Nov 20 2000

Status

approved