

A096970


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 the same row or column.


9




OFFSET

1,2


COMMENTS

Suggested by Leroy Quet, Jul 05 2004.
For n >= 2, number of (directed) Hamiltonian paths on the n X n rook graph.  Eric W. Weisstein, Dec 16 2013


LINKS

Table of n, a(n) for n=1..7.
Eric Weisstein's World of Mathematics, Hamiltonian Path
Eric Weisstein's World of Mathematics, Rook Graph
Index entries for sequences related to graphs, Hamiltonian


EXAMPLE

Among the 4 X 4 grids counted is:
1 2 3 10
15 6 5 11
14 13 4 12
16 7 8 9


CROSSREFS

Cf. A096969, A269561, A269565.
Sequence in context: A172938 A252176 A252763 * A248386 A114617 A162014
Adjacent sequences: A096967 A096968 A096969 * A096971 A096972 A096973


KEYWORD

nonn,more,hard


AUTHOR

John W. Layman, Jul 16 2004


EXTENSIONS

a(5) from Eric W. Weisstein, Dec 28 2013
a(6)a(7) from Andrew Howroyd, Feb 29 2016


STATUS

approved



