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A184035 1/16 the number of (n+1) X 6 0..3 arrays with all 2 X 2 subblocks having the same four values. 1
169, 181, 202, 244, 322, 478, 778, 1378, 2554, 4906, 9562, 18874, 37402, 74458, 148378, 296218, 591514, 1182106, 2362522, 4723354, 9443482, 18883738, 37761178, 75516058, 151019674, 302026906, 604029082, 1208033434, 2416017562, 4831985818 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 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*(169 - 326*x - 341*x^2 + 652*x^3) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)).

a(n) = 9*2^(n/2-1) + 9*2^(n-1) + 154 for n even.

a(n) = 9*2^(n-1) + 3*2^((n+1)/2) + 154 for n odd.

(End)

EXAMPLE

Some solutions for 3 X 6:

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

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

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

CROSSREFS

Cf. A184039.

Sequence in context: A003929 A343269 A240069 * A044869 A260055 A235718

Adjacent sequences:  A184032 A184033 A184034 * A184036 A184037 A184038

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 08 2011

STATUS

approved

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Last modified June 23 04:15 EDT 2021. Contains 345395 sequences. (Running on oeis4.)