1,1
See reference for more information.
I. P. Goulden, J. H. Kwak and J. Lee, Enumerating branched orientable surface coverings over a non-orientable surface, Discr. Math. 303 (2005), 42-55.
Sequence in context: A140285 A198911 A206513 * A198521 A068732 A174304
Adjacent sequences: A112611 A112612 A112613 * A112615 A112616 A112617
nonn,bref
N. J. A. Sloane (njas(AT)research.att.com), Dec 23 2005