1,3
The old entry with this sequence number was a duplicate of A057237.
M. Maia and M. Mendez, On the arithmetic product of combinatorial species, Discr. Math., 308 (2008), 5407-5427.
Sequence in context: A008509 A081868 A193652 * A006092 A015859 A022427
Adjacent sequences: A092983 A092984 A092985 * A092987 A092988 A092989
nonn
N. J. A. Sloane (njas(AT)research.att.com), Nov 04 2008