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A220275 Equals two maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX2 array 1
1, 6, 25, 87, 322, 1168, 4303, 15680, 57251, 209919, 765897, 2798292, 10239771, 37404529, 136700188, 499846884, 1826552660, 6675971458, 24404489928, 89191936887, 325998995843, 1191600903496, 4355213008401, 15918480514002 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A220279

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

EXAMPLE

Some solutions for n=3

..0..0....1..0....0..0....1..1....0..0....1..1....0..0....1..1....0..0....1..0

..0..0....0..0....1..1....1..0....1..1....1..1....1..0....0..0....0..0....0..0

..0..1....0..0....0..0....0..0....1..0....1..1....0..0....1..0....1..1....1..0

CROSSREFS

Sequence in context: A164271 A233698 A230723 * A055585 A099625 A209243

Adjacent sequences:  A220272 A220273 A220274 * A220276 A220277 A220278

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 09 2012

STATUS

approved

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Last modified May 27 02:54 EDT 2019. Contains 323597 sequences. (Running on oeis4.)