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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, 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 (list; table; graph; refs; listen; history; text; internal format)
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: A290772 A055535 A072217 * A281139 A052686 A258781

Adjacent sequences:  A229426 A229427 A229428 * A229430 A229431 A229432

KEYWORD

nonn,tabl

AUTHOR

Jens Voß, Sep 23 2013

STATUS

approved

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Last modified June 15 17:43 EDT 2019. Contains 324142 sequences. (Running on oeis4.)