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A221292 Equals two maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 4Xn array 0
1, 37, 556, 9107, 172904, 2890017, 49684593, 821323042, 13475380990 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A221290

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

Some solutions for n=3

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

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

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

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

CROSSREFS

Sequence in context: A219440 A219141 A220938 * A231514 A156226 A217501

Adjacent sequences:  A221289 A221290 A221291 * A221293 A221294 A221295

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 09 2013

STATUS

approved

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Last modified June 18 20:45 EDT 2021. Contains 345121 sequences. (Running on oeis4.)