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 A145157 #29 Dec 20 2024 10:44:53 %S A145157 1,2,8,52,824,22144,1510446,180160012,54986690944,29805993260994, %T A145157 41433610713353366,103271401574007978038,660340630211753942588170, %U A145157 7618229614763015717175450784,225419381425094248494363948728158 %N A145157 Number of Greek-key tours on an n X n board; i.e., self-avoiding walks on n X n grid starting in top left corner. %C A145157 The sequence may be enumerated using standard methods for counting Hamiltonian cycles on a modified graph with two additional nodes, one joined to a corner vertex and the other joined to all other vertices. - _Andrew Howroyd_, Nov 08 2015 %H A145157 Nathaniel Johnston, <a href="http://www.njohnston.ca/2009/05/on-maximal-self-avoiding-walks">On Maximal Self-Avoiding Walks</a> %H A145157 Ville H. Pettersson, <a href="http://www.combinatorics.org/ojs/index.php/eljc/article/view/v21i4p7">Enumerating Hamiltonian Cycles</a>, The Electronic Journal of Combinatorics, Volume 21, Issue 4, 2014. %Y A145157 Main diagonal of A378938. %Y A145157 Cf. A046994, A046995, A145156, A160240, A160241. %Y A145157 Cf. A000532, A001184, A120443, A003763, A271507, A007764. %K A145157 hard,nonn,walk %O A145157 1,2 %A A145157 _Nathaniel Johnston_, Oct 03 2008 %E A145157 a(9)-a(15) from _Andrew Howroyd_, Nov 08 2015