1,2
See reference for more information.
Table of n, a(n) for n=1..5.
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: A102303 A231310 A009060 * A197673 A012089 A343133
Adjacent sequences: A112613 A112614 A112615 * A112617 A112618 A112619
nonn,more
N. J. A. Sloane, Dec 23 2005
approved
