This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A214816 #21 Jan 27 2025 14:27:39 %S A214816 1,2,5,20,96,644,5839,67834,970568,16256556,308620966,6506035400, %T A214816 150358570914,3775903806928,102348067516576,2977979542305736, %U A214816 92579723269733557,3062602106878957610,107418879166917701583,3981908920500346885116,155550644128029095714786 %N A214816 Number of unsensed combinatorial maps with n edges on an orientable surface of any genus. %H A214816 Andrew Howroyd, <a href="/A214816/b214816.txt">Table of n, a(n) for n = 0..30</a> %H A214816 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. %H A214816 Timothy R. Walsh, <a href="http://www.info2.uqam.ca/~walsh_t/papers/GENERATING NONISOMORPHIC.pdf">Space-efficient generation of nonisomorphic maps and hypermaps</a>. %H A214816 T. R. Walsh, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/Walsh/walsh3.html">Space-Efficient Generation of Nonisomorphic Maps and Hypermaps</a>, J. Int. Seq. 18 (2015) # 15.4.3. %F A214816 a(n) = (A170946(n) + A170947(n)) / 2. [Breda d'Azevedo, Mednykh & Nedela, Corollary 4.7] - _Andrey Zabolotskiy_, Jun 06 2024 %Y A214816 Row sums of A379439. %Y A214816 Cf. A006385, A006387, A170946 (sensed), A170947 (achiral), A170948 (chiral pairs), A214814, A214815, A297880, A297881, A348798, A348800, A348801. %K A214816 nonn %O A214816 0,2 %A A214816 _N. J. A. Sloane_, Jul 31 2012 %E A214816 a(12)-a(18) from _Andrey Zabolotskiy_, Jun 06 2024 %E A214816 a(19) onwards from _Andrew Howroyd_, Jan 27 2025