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A204752 Number of (n+2) X 8 0..1 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..1 introduced in row major order. 1
590, 49, 48, 53, 61, 74, 95, 129, 184, 273, 417, 650, 1027, 1637, 2624, 4221, 6805, 10986, 17751, 28697, 46408, 75065, 121433, 196458, 317851, 514269, 832080, 1346309, 2178349, 3524618, 5702927, 9227505, 14930392, 24157857, 39088209 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 6 of A204754.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) - a(n-3) for n>5.

Empirical g.f.: x*(590 - 1131*x - 50*x^2 + 547*x^3 + 4*x^4) / ((1 - x)*(1 - x - x^2)). - Colin Barker, Jun 10 2018

EXAMPLE

Some solutions for n=3:

  0 1 1 0 0 1 1 0      0 1 1 0 0 1 0 0      0 1 1 0 1 0 1 1

  0 1 1 0 0 1 1 0      0 1 1 0 0 1 0 0      0 1 1 0 1 0 1 1

  0 1 1 0 0 1 1 0      0 1 1 0 0 1 0 0      0 1 1 0 1 0 1 1

  0 1 1 0 0 1 1 0      0 1 1 0 0 1 0 0      0 1 1 0 1 0 1 1

  0 1 1 0 0 1 1 0      0 1 1 0 0 1 0 0      0 1 1 0 1 0 1 1

CROSSREFS

Cf. A204754.

Sequence in context: A210894 A145699 A203628 * A320713 A116170 A171724

Adjacent sequences:  A204749 A204750 A204751 * A204753 A204754 A204755

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 18 2012

STATUS

approved

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Last modified September 19 03:31 EDT 2021. Contains 347550 sequences. (Running on oeis4.)