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A220374 Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and vertical neighbors in a random 0..2 nX4 array 0
4, 94, 2095, 39780, 722126, 12480964, 209958887, 3466406061 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A220375

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A116291 A061992 A221389 * A220429 A210857 A220682

Adjacent sequences:  A220371 A220372 A220373 * A220375 A220376 A220377

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 13 2012

STATUS

approved

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Last modified December 1 11:03 EST 2021. Contains 349429 sequences. (Running on oeis4.)