A229429 Number of ways to label the cells of an m-by-n grid such that no (orthogonally) adjacent cells have adjacent labels; square array A(m,n) read by antidiagonals

1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 2, 24, 24, 2, 1, 1, 14, 1660, 12072, 1660, 14, 1, 1, 90, 160524, 16595940, 16595940, 160524, 90, 1, 1, 646, 21914632, 46053512896, 696497375736, 46053512896, 21914632, 646, 1

Offset

0,17

Links

Table of n, a(n) for n=0..44.

Example

The A(2,3) = 24 valid labelings of a 2-by-3 grid are
   153   163   135   513   415   416
   426   425   462   246   263   253
together with their 18 reflections and rotations.
The square array starts:
1,   1,   1,   1,   1,   1,  ...
1,   1,   0,   0,   2,  ...
1,   0,   0,  24,  ...
1,   0,  24,  ...
1,   2,  ...
1,  ...

Crossrefs

A(1, n) = A002464(n), A(2, n) = A229430(n)

Sequence in context: A342545 A055535 A072217 * A281139 A052686 A258781

Adjacent sequences: A229426 A229427 A229428 * A229430 A229431 A229432

Keyword

nonn,tabl

Author

Jens Voß, Sep 23 2013

Status

approved