This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Number of directed Hamiltonian paths in (n X n)-grid graph. - Max Alekseyev, May 03 2009 LINKS Andrew Howroyd, Table of n, a(n) for n = 1..17 Eric Weisstein's World of Mathematics, Grid Graph Eric Weisstein's World of Mathematics, Hamiltonian Path 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 Cf. A120443, A096970. Cf. A143246, A137891, A158651. - Max Alekseyev, May 03 2009 Sequence in context: A158922 A117083 A007987 * A209829 A209848 A093104 Adjacent sequences:  A096966 A096967 A096968 * A096970 A096971 A096972 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.