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A204380 Number of (n+2) X 9 0..1 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..1 introduced in row major order. 1
439, 193, 205, 217, 241, 283, 347, 453, 625, 901, 1349, 2075, 3247, 5145, 8217, 13185, 21225, 34235, 55283, 89341, 144449, 233613, 377885, 611323, 989031, 1600177, 2589033, 4189033, 6777889, 10966747, 17744459, 28711029, 46455313, 75166165 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A204381.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) -a(n-4) -a(n-5) for n>8.

Empirical g.f.: x*(439 - 246*x - 427*x^2 - 620*x^3 + 65*x^4 + 252*x^5 + 4*x^6 + 4*x^7) / ((1 - x)*(1 - x - x^2)*(1 + x + x^2)). - Colin Barker, Jun 07 2018

EXAMPLE

Some solutions for n=3:

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

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

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

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

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

CROSSREFS

Cf. A204381.

Sequence in context: A043447 A006911 A222877 * A185683 A142753 A142141

Adjacent sequences:  A204377 A204378 A204379 * A204381 A204382 A204383

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 14 2012

STATUS

approved

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Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)