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A184046 1/9 the number of (n+1) X 8 0..2 arrays with all 2 X 2 subblocks having the same four values. 1
289, 295, 305, 325, 361, 433, 569, 841, 1369, 2425, 4505, 8665, 16921, 33433, 66329, 132121, 263449, 526105, 1050905, 2100505, 4198681, 8395033, 16785689, 33567001, 67125529, 134242585, 268468505, 536920345, 1073807641, 2147582233, 4295098649 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A184048.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 3*a(n-1) - 6*a(n-3) + 4*a(n-4).

Conjectures from Colin Barker, Apr 10 2018: (Start)

G.f.: x*(289 - 572*x - 580*x^2 + 1144*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).

a(n) = 3*2^(n/2) + 2^(n+1) + 281 for n even.

a(n) = 2^(n+1) + 2^((n+3)/2) + 281 for n odd.

(End)

EXAMPLE

Some solutions for 5 X 8:

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

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

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

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

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

CROSSREFS

Cf. A184048.

Sequence in context: A107739 A221203 A188367 * A235810 A229906 A008367

Adjacent sequences:  A184043 A184044 A184045 * A184047 A184048 A184049

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 08 2011

STATUS

approved

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Last modified January 20 02:13 EST 2019. Contains 319320 sequences. (Running on oeis4.)