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A230927 Number of black-square subarrays of (n+2)X(n+2) 0..3 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero 0
2, 6, 102, 1242, 98296, 4092246, 1088383766, 159130979900, 148986525600652, 76371552378548280, 250772217069255837720 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Diagonal of A230935

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

Some solutions for n=4

..x..0..x..2..x..2....x..0..x..2..x..2....x..0..x..0..x..2....x..0..x..0..x..2

..1..x..3..x..3..x....1..x..3..x..3..x....3..x..1..x..3..x....3..x..1..x..3..x

..x..2..x..0..x..0....x..2..x..0..x..2....x..2..x..0..x..0....x..2..x..2..x..2

..1..x..1..x..1..x....1..x..3..x..1..x....1..x..1..x..1..x....1..x..3..x..1..x

..x..0..x..2..x..0....x..2..x..2..x..0....x..2..x..0..x..2....x..0..x..0..x..0

..3..x..3..x..3..x....1..x..1..x..3..x....1..x..3..x..3..x....3..x..3..x..3..x

CROSSREFS

Sequence in context: A066091 A100704 A123257 * A054247 A278888 A099790

Adjacent sequences:  A230924 A230925 A230926 * A230928 A230929 A230930

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 01 2013

STATUS

approved

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Last modified August 7 17:44 EDT 2020. Contains 336278 sequences. (Running on oeis4.)