A170948 - OEIS

%I #14 Jan 27 2025 14:25:59

%S 0,0,0,0,11,226,3597,55006,892791,15763270,305360481,6483720916,

%T 150200835113,3774756521566,102339496556342,2977913930684928,

%U 92579209306356230,3062597993515937128,107418845568842941190,3981908640735783136040,155550641755207044201203

%N Number of chiral pairs of combinatorial maps with n edges.

%H Andrew Howroyd, <a href="/A170948/b170948.txt">Table of n, a(n) for n = 0..30</a>

%H Antonio Breda d'Azevedo, Alexander Mednykh, and Roman Nedela, <a href="https://doi.org/10.1016/j.disc.2009.11.017">Enumeration of maps regardless of genus: Geometric approach</a>, Discrete Mathematics, Volume 310, 2010, Pages 1184-1203.

%F a(n) = (A170946(n) - A170947(n)) / 2. [Breda d'Azevedo, Mednykh & Nedela, Corollary 4.8] - _Andrey Zabolotskiy_, Jun 06 2024

%Y Cf. A170946 (sensed), A170947 (achiral), A214816 (unsensed).

%K nonn

%O 0,5

%A _N. J. A. Sloane_, Feb 21 2010

%E Name clarified, a(0)=0 prepended and a(19) onwards added by _Andrew Howroyd_, Jan 27 2025