OFFSET
1,2
LINKS
P. J. Cameron, M. Gadouleau, J. D. Mitchell, Y. Peresse, Chains of subsemigroups, arXiv preprint arXiv:1501.06394 [math.GR], 2015.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Sep 21 2015
STATUS
approved