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A184033 1/16 the number of (n+1) X 4 0..3 arrays with all 2 X 2 subblocks having the same four values. 1
49, 61, 82, 124, 202, 358, 658, 1258, 2434, 4786, 9442, 18754, 37282, 74338, 148258, 296098, 591394, 1181986, 2362402, 4723234, 9443362, 18883618, 37761058, 75515938, 151019554, 302026786, 604028962, 1208033314, 2416017442, 4831985698 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A184039.

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*(49 - 86*x - 101*x^2 + 172*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).

a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 34 for n even.

a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 34 for n odd.

(End)

EXAMPLE

Some solutions for 3 X 4:

..0..0..1..2....0..1..0..1....0..2..3..2....2..2..2..2....1..3..1..3

..1..2..0..0....3..2..3..2....3..0..0..0....0..0..0..0....3..2..3..2

..0..0..1..2....1..0..1..0....0..2..3..2....2..2..2..2....1..3..1..3

CROSSREFS

Cf. A184039.

Sequence in context: A039472 A135145 A111327 * A178951 A202001 A038640

Adjacent sequences:  A184030 A184031 A184032 * A184034 A184035 A184036

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 08 2011

STATUS

approved

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Last modified January 20 09:55 EST 2022. Contains 350471 sequences. (Running on oeis4.)