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A231645 Number of n X 2 0..2 arrays with no element less than a strict majority of its horizontal and vertical neighbors. 2
3, 35, 104, 341, 1189, 4040, 13560, 45803, 155131, 524683, 1773770, 5998876, 20290918, 68629108, 232120783, 785115525, 2655576210, 8982247095, 30381769982, 102764504913, 347595681724, 1175726561166, 3976846922803, 13451535863780 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A231651.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) - 12*a(n-2) + 19*a(n-3) - 32*a(n-4) + 15*a(n-5) - 13*a(n-6) + 13*a(n-7) + 10*a(n-8) + 7*a(n-9) + 5*a(n-10) + a(n-11) for n>12.

Empirical g.f.: x*(3 + 17*x - 70*x^2 + 80*x^3 - 178*x^4 + 97*x^5 - 49*x^6 + 100*x^7 + 73*x^8 + 48*x^9 + 31*x^10 + 6*x^11) / (1 - 6*x + 12*x^2 - 19*x^3 + 32*x^4 - 15*x^5 + 13*x^6 - 13*x^7 - 10*x^8 - 7*x^9- 5*x^10 - x^11). - Colin Barker, Mar 18 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Cf. A231651.

Sequence in context: A246824 A001539 A113854 * A076376 A133710 A130061

Adjacent sequences:  A231642 A231643 A231644 * A231646 A231647 A231648

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 12 2013

STATUS

approved

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Last modified March 31 03:48 EDT 2020. Contains 333136 sequences. (Running on oeis4.)