OFFSET
2,5
LINKS
P. J. Cameron, M. Gadouleau, J. D. Mitchell, Y. Peresse, Chains of subsemigroups, arXiv preprint arXiv:1501.06394 [math.GR], 2015.
EXAMPLE
Triangle begins:
0,
0,1,
0,3,2,
0,6,12,4
0,12,40,30,6
0,20,100,150,66,9
...
CROSSREFS
KEYWORD
AUTHOR
N. J. A. Sloane, Sep 21 2015
STATUS
approved