OFFSET
1,1
LINKS
Antonio Breda d'Azevedo, Alexander Mednykh, and Roman Nedela, Table of n, a(n) for n = 1..30
Antonio Breda d'Azevedo, Alexander Mednykh, and Roman Nedela, Enumeration of maps regardless of genus: Geometric approach, Discrete Mathematics, Volume 310, 2010, Pages 1184-1203.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 21 2010
STATUS
approved