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A096969
Number of ways to number the cells of an n X n square grid with 1,2,3,...,n^2 so that successive integers are in adjacent cells (horizontally or vertically).
5
1, 8, 40, 552, 8648, 458696, 27070560, 6046626568, 1490832682992, 1460089659025264, 1573342970540617696, 6905329711608694708440, 33304011435341069362631160, 663618176813467308855850585056, 14527222735920532980525200234503048
OFFSET
1,2
COMMENTS
Number of directed Hamiltonian paths in (n X n)-grid graph. - Max Alekseyev, May 03 2009
LINKS
Stéphane Duguay and Steven Pigeon, Comparison of Pixel Correlation Induced by Space-Filling Curves on 2D Image Data, The 10th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications (Metz, France, 2019) Vol. 1, 294-297.
Mary Grace Hanson and David A. Nash, Minimal and maximal Numbrix puzzles, arXiv:1706.09389 [math.CO], 2017.
Eric Weisstein's World of Mathematics, Grid Graph
Eric Weisstein's World of Mathematics, Hamiltonian Path
FORMULA
Conjecture: Limit_{n->oo} log_(n+1)!(a(n+1)) - log_n!(a(n)) = c, where 0.09 < c < 0.11. - Nicolas Bělohoubek, Jun 12 2022
EXAMPLE
One of the 8648 numberings of a 5 X 5 grid is
.
3---2---1 20--21
| | |
4 17--18--19 22
| | |
5 16--15--14 23
| | |
6 9--10 13 24
| | | | |
7---8 11--12 25
CROSSREFS
KEYWORD
nonn,walk
AUTHOR
John W. Layman, Jul 16 2004, at the suggestion of Leroy Quet, Jul 05 2004
EXTENSIONS
a(7) from Giovanni Resta, May 12 2006
a(8)-a(15) added by Andrew Howroyd, Dec 20 2015
STATUS
approved