OFFSET
1,2
LINKS
N. J. A. Sloane, Overview of A001329, A001423-A001428, A258719, A258720.
T. Tamura, Some contributions of computation to semigroups and groupoids, pp. 229-261 of J. Leech, editor, Computational Problems in Abstract Algebra. Pergamon, Oxford, 1970. (Annotated and scanned copy)
FORMULA
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 18 2015
EXTENSIONS
Terms a(5) and beyond from Andrew Howroyd, May 06 2023
STATUS
approved