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A230984 Number of white square subarrays of (n+1) X (3+1) binary arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with upper left element zero. 2
2, 4, 11, 24, 59, 139, 332, 796, 1903, 4563, 10934, 26209, 62835, 150636, 361156, 865882, 2076002, 4977375, 11933643, 28611925, 68599559, 164473454, 394339672, 945464381, 2266835107, 5434939417, 13030752556, 31242393432, 74906430076 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A230989.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 3*a(n-3) - 6*a(n-4) + 2*a(n-5) + 4*a(n-6) - a(n-7) - a(n-8).

Empirical g.f.: x*(2 - 3*x^2 - 4*x^3 + 2*x^4 + 2*x^5 - x^6) / (1 - 2*x - 3*x^2 + 3*x^3 + 6*x^4 - 2*x^5 - 4*x^6 + x^7 + x^8). - Colin Barker, Mar 18 2018

EXAMPLE

Some solutions for n=6:

..0..x..0..x....0..x..1..x....0..x..0..x....0..x..1..x....0..x..0..x

..x..1..x..1....x..1..x..0....x..1..x..0....x..1..x..0....x..1..x..1

..1..x..0..x....0..x..1..x....1..x..1..x....1..x..0..x....0..x..0..x

..x..0..x..0....x..1..x..0....x..0..x..0....x..0..x..1....x..1..x..1

..1..x..1..x....0..x..0..x....1..x..1..x....1..x..0..x....1..x..0..x

..x..0..x..1....x..0..x..1....x..0..x..0....x..1..x..1....x..0..x..1

..1..x..0..x....1..x..1..x....1..x..1..x....0..x..0..x....1..x..1..x

CROSSREFS

Cf. A230989.

Sequence in context: A034485 A018006 A183510 * A196195 A205500 A342533

Adjacent sequences:  A230981 A230982 A230983 * A230985 A230986 A230987

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 02 2013

STATUS

approved

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Last modified October 5 11:53 EDT 2022. Contains 357255 sequences. (Running on oeis4.)