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A229840 Number of n X n 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value 2-x(i,j) 0
0, 15, 987, 453837, 1296261759, 23643209345079, 2745117942652795617 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A229847

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

Some solutions for n=3

..0..2..0....1..1..2....0..0..0....2..0..2....1..1..1....1..2..0....1..0..0

..1..0..0....1..1..0....2..2..2....1..1..2....0..2..1....1..0..2....1..2..2

..1..2..2....1..1..2....2..0..0....2..0..0....0..2..0....1..2..0....2..0..0

CROSSREFS

Sequence in context: A055413 A067408 A274713 * A102102 A196569 A019282

Adjacent sequences:  A229837 A229838 A229839 * A229841 A229842 A229843

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 01 2013

STATUS

approved

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Last modified December 16 09:06 EST 2019. Contains 330020 sequences. (Running on oeis4.)