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A231221 Number of (n+2) X (2+2) 0..2 arrays with no element unequal to a strict majority of its horizontal, vertical, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order. 1
2, 4, 8, 17, 45, 103, 264, 676, 1724, 4501, 11679, 30579, 80180, 210494, 553858, 1457853, 3840945, 10124071, 26693522, 70402100, 185706800, 489925347, 1292616577, 3410640207, 8999588762, 23747752874, 62666069376, 165367179091 (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) = 3*a(n-1) + 2*a(n-2) - 6*a(n-3) - 7*a(n-4) + 5*a(n-5) - a(n-6) + 6*a(n-7) + 17*a(n-8) - 20*a(n-9) - 2*a(n-10) + 4*a(n-11).

Empirical g.f.: x*(2 - 2*x - 8*x^2 - 3*x^3 + 16*x^4 + 5*x^6 + 19*x^7 - 34*x^8 - 2*x^9 + 8*x^10) / ((1 - x)*(1 - 2*x - 4*x^2 + 2*x^3 + 9*x^4 + 4*x^5 + 5*x^6 - x^7 - 18*x^8 + 2*x^9 + 4*x^10)). - Colin Barker, Sep 27 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

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

CROSSREFS

Column 2 of A231227.

Sequence in context: A200542 A272105 A283162 * A231435 A113153 A255999

Adjacent sequences:  A231218 A231219 A231220 * A231222 A231223 A231224

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 05 2013

STATUS

approved

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Last modified October 4 21:22 EDT 2022. Contains 357240 sequences. (Running on oeis4.)