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A221187 Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..2 nX4 array 0
4, 107, 2648, 51924, 928133, 15638551, 256020803 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A221188

LINKS

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

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A087178 A104595 A222930 * A220531 A322085 A128865

Adjacent sequences:  A221184 A221185 A221186 * A221188 A221189 A221190

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 04 2013

STATUS

approved

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Last modified January 20 08:18 EST 2020. Contains 331081 sequences. (Running on oeis4.)