OFFSET
1,2
COMMENTS
Might be thought of as number of rooted (-1)-dimensional "polycubes" with n cells, with no symmetries removed.
REFERENCES
Dan Hoey, Bill Gosper and Richard C. Schroeppel, Discussions in Math-Fun Mailing list, circa Jul 13 1999.
LINKS
R. C. Schroeppel, A few mathematical experiments
CROSSREFS
KEYWORD
sign
AUTHOR
STATUS
approved