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A204367 Number of (n+2) X 7 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..2 introduced in row major order. 1
2419, 1715, 1042, 1264, 1984, 3280, 7376, 18776, 48392, 130552, 355336, 966472, 2638568, 7207496, 19684040, 53775496, 146916424, 401370184, 1096560584, 2995858760, 8184813896, 22361322568, 61092269896, 166907137864, 455998772552 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A204370.

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>9.

Empirical g.f.: x*(2419 - 5542*x - 4103*x^2 - 1862*x^3 + 12706*x^4 + 7618*x^5 - 5888*x^6 - 2628*x^7 - 200*x^8) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Feb 16 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A256835 A237940 A097030 * A131759 A254901 A254908

Adjacent sequences:  A204364 A204365 A204366 * A204368 A204369 A204370

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 14 2012

STATUS

approved

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Last modified November 12 19:19 EST 2018. Contains 317116 sequences. (Running on oeis4.)