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A231134 Number of (n+1) X (2+1) black-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order. 1
2, 9, 40, 182, 808, 3688, 16368, 74728, 331648, 1514160, 6719936, 30680320, 136161152, 621652928, 2758934016, 12596099456, 55902265856, 255225567744, 1132706802688, 5171449356800, 22951211032576, 104785303002112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 22*a(n-2) - 36*a(n-4) + 16*a(n-6).

Empirical g.f.: x*(2 + 9*x - 4*x^2 - 16*x^3 + 8*x^5) / (1 - 22*x^2 + 36*x^4 - 16*x^6). - Colin Barker, Sep 26 2018

EXAMPLE

Some solutions for n=5:

..x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x

..1..x..2....1..x..0....1..x..2....1..x..1....0..x..1....0..x..1....1..x..2

..x..1..x....x..2..x....x..1..x....x..2..x....x..1..x....x..2..x....x..0..x

..0..x..0....0..x..0....0..x..1....1..x..1....2..x..0....2..x..0....1..x..2

..x..1..x....x..2..x....x..0..x....x..2..x....x..2..x....x..1..x....x..0..x

..2..x..0....1..x..0....2..x..2....0..x..0....0..x..0....2..x..0....2..x..2

CROSSREFS

Column 2 of A231137.

Sequence in context: A020728 A107979 A021001 * A038112 A268039 A235596

Adjacent sequences:  A231131 A231132 A231133 * A231135 A231136 A231137

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2013

STATUS

approved

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Last modified January 19 17:59 EST 2020. Contains 331051 sequences. (Running on oeis4.)