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A205355 Number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having the same number of equal diagonal or antidiagonal elements, and new values 0..2 introduced in row major order. 1
50, 275, 1562, 8948, 51458, 296774, 1716002, 9946442, 57787010, 336482834, 1963466114, 11480698658, 67259440130, 394759998530, 2320933378562, 13667740361858, 80610335471618, 476103197966594, 2815694162688002 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A205361.

LINKS

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

FORMULA

Empirical: a(n) = 15*a(n-1) - 76*a(n-2) + 146*a(n-3) - 84*a(n-4).

Empirical g.f.: x*(50 - 475*x + 1237*x^2 - 882*x^3) / ((1 - x)*(1 - 6*x)*(1 - 8*x + 14*x^2)). - Colin Barker, Jun 11 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A205361.

Sequence in context: A091414 A186123 A220864 * A172519 A046656 A205620

Adjacent sequences:  A205352 A205353 A205354 * A205356 A205357 A205358

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 26 2012

STATUS

approved

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Last modified January 22 15:13 EST 2022. Contains 350481 sequences. (Running on oeis4.)