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A241133 Number of n X 2 0..2 arrays with no element equal to the same number of vertical neighbors as horizontal neighbors, with new values 0..2 introduced in row major order. 1
1, 2, 5, 17, 56, 195, 691, 2476, 8941, 32393, 117632, 427635, 1555643, 5661060, 20604893, 75004865, 273044808, 994013923, 3618750915, 13174348572, 47962513037, 174612764153, 635697854288, 2314333217939, 8425607885003 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) + 2*a(n-2) - 11*a(n-3) - 6*a(n-4) + 8*a(n-5) for n>6.

Empirical g.f.: x*(1 - x)*(1 - x - 6*x^2 - 2*x^3 + 4*x^4) / ((1 - 2*x)*(1 - 2*x - 6*x^2 - x^3 + 4*x^4)). - Colin Barker, Oct 29 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 2 of A241138.

Sequence in context: A159866 A042671 A180148 * A148410 A190531 A148411

Adjacent sequences:  A241130 A241131 A241132 * A241134 A241135 A241136

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 16 2014

STATUS

approved

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Last modified April 10 17:00 EDT 2021. Contains 342852 sequences. (Running on oeis4.)