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: A074488 A059950 A140285 this_sequence A068732 A068939 A157643

Adjacent sequences: A112611 A112612 A112613 this_sequence A112615 A112616 A112617

nonn,bref

N. J. A. Sloane (njas(AT)research.att.com), Dec 23 2005