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A236157 Number of (n+1) X (1+1) 0..2 arrays colored with the sets of distinct values in every 2 X 2 subblock, with new values 0..2 introduced row-major order. 1
14, 69, 358, 1844, 9522, 49108, 253476, 1307604, 6748036, 34815556, 179654284, 926952404, 4783063596, 24679485652, 127343933580, 657071270292, 3390407179468, 17493950046676, 90266392976908, 465760736729108 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 18*a(n-2) + 16*a(n-3) + 12*a(n-4) - 12*a(n-5) for n>6.

Empirical g.f.: x*(14 + 55*x + 37*x^2 + 20*x^3 - 38*x^4 + 6*x^5) / (1 - x - 18*x^2 - 16*x^3 - 12*x^4 + 12*x^5). - Colin Barker, Oct 20 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Column 1 of A236164.

Sequence in context: A249708 A008354 A051879 * A002423 A212751 A212749

Adjacent sequences:  A236154 A236155 A236156 * A236158 A236159 A236160

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 19 2014

STATUS

approved

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Last modified May 11 21:35 EDT 2021. Contains 343808 sequences. (Running on oeis4.)