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 A206346 #17 Aug 01 2025 11:09:52 %S A206346 0,1,1,4,8,58,177,2196,11091,172522,1239350,20916154,197149146 %N A206346 Number of solvable clock puzzles with n positions in Final Fantasy XIII-2, up to rotation and reflection. %C A206346 Equals the number of Hamiltonian directed graphs on n vertices with the properties that: (1) every vertex has outdegree 1 or 2; and (2) the vertices can be arranged in a circle so that the directed edges leaving each vertex are symmetric about that vertex (e.g., if there is a directed edge that points two vertices in the clockwise direction, then the other one must point two vertices in the counterclockwise direction). %C A206346 The same as A206345, except clock puzzles that are simply rotations or reflections of each other are not counted multiple times. %H A206346 Nathaniel Johnston, <a href="http://www.njohnston.ca/2012/02/counting-and-solving-final-fantasy-xiii-2s-clock-puzzles/">Counting and Solving Final Fantasy XIII-2's Clock Puzzles</a>. %Y A206346 Cf. A206344, A206345. %K A206346 nonn,more %O A206346 1,4 %A A206346 _Nathaniel Johnston_, Feb 06 2012 %E A206346 a(6)-a(9) corrected, a(10)-a(13) added by _Max Alekseyev_, Jul 31 2025