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A204281 Number of (n+2) X 7 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..2 introduced in row major order. 1
5263, 539, 334, 442, 736, 996, 2168, 5368, 13024, 34864, 94528, 255360, 696608, 1902112, 5191264, 14181088, 38741728, 105833952, 289140704, 789944032, 2158146784, 5896160992, 16108605664, 44009488608, 120236147936, 328491253984 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A204284.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -6*a(n-4) +4*a(n-6) for n>8.

Empirical g.f.: x*(5263 - 15250*x - 1283*x^2 - 560*x^3 + 30988*x^4 + 2022*x^5 - 19868*x^6 - 640*x^7) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Jun 06 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Cf. A204284.

Sequence in context: A206379 A234229 A143936 * A251901 A274361 A223494

Adjacent sequences:  A204278 A204279 A204280 * A204282 A204283 A204284

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 13 2012

STATUS

approved

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Last modified December 9 08:41 EST 2021. Contains 349627 sequences. (Running on oeis4.)