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A209808 Number of (n+1) X 3 0..3 arrays with every 2 X 2 subblock having two distinct values, and new values 0..3 introduced in row major order. 1
34, 302, 2721, 25505, 244208, 2377378, 23398105, 231987361, 2311229272, 23098641162, 231319042937, 2319549963665, 23278778523264, 233749081336914, 2347950341283193, 23589750833899361, 237038455370387400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A209814.

LINKS

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

FORMULA

Empirical: a(n) = 17*a(n-1) - 68*a(n-2) - 56*a(n-3) + 397*a(n-4) - 181*a(n-5) - 264*a(n-6) + 108*a(n-7).

Empirical g.f.: x*(34 - 276*x - 101*x^2 + 1688*x^3 - 935*x^4 - 1182*x^5 + 504*x^6) / ((1 - 6*x - 3*x^2 + 2*x^3)*(1 - 11*x + 5*x^2 + 51*x^3 - 54*x^4)). - Colin Barker, Jul 13 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A209814.

Sequence in context: A156531 A220565 A230803 * A160146 A101092 A233061

Adjacent sequences:  A209805 A209806 A209807 * A209809 A209810 A209811

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 13 2012

STATUS

approved

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Last modified May 19 04:06 EDT 2019. Contains 323377 sequences. (Running on oeis4.)