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A214816
Number of unsensed maps with n edges on a surface of genus g, summed on g = 0 through [n/2].
8
1, 2, 5, 20, 96, 644, 5839, 67834, 970568, 16256556, 308620966, 6506035400, 150358570914, 3775903806928, 102348067516576, 2977979542305736, 92579723269733557, 3062602106878957610, 107418879166917701583
OFFSET
0,2
LINKS
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.
T. R. Walsh, Space-Efficient Generation of Nonisomorphic Maps and Hypermaps, J. Int. Seq. 18 (2015) # 15.4.3.
FORMULA
a(n) = (A170946(n) + A170947(n)) / 2. [Breda d'Azevedo, Mednykh & Nedela, Corollary 4.7] - Andrey Zabolotskiy, Jun 06 2024
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 31 2012
EXTENSIONS
Terms a(12) and beyond from Andrey Zabolotskiy, Jun 06 2024
STATUS
approved