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A205020 Number of (n+1)X2 0..3 arrays with the determinants of 2X2 subblocks nondecreasing rightwards and downwards 2
256, 2338, 15040, 84899, 456043, 2470216, 13615376, 76027865, 427451825, 2411941887, 13634285159, 77146583419, 436735262905, 2473069283987, 14006039121985, 79328088635035, 449320047871193, 2545034872510264 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A205027

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) -15*a(n-2) -41*a(n-3) +120*a(n-4) -72*a(n-5) for n>21

EXAMPLE

Some solutions for n=4

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

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

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

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

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

CROSSREFS

Sequence in context: A205635 A205027 A207300 * A204309 A235416 A235261

Adjacent sequences:  A205017 A205018 A205019 * A205021 A205022 A205023

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 21 2012

STATUS

approved

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Last modified October 17 06:40 EDT 2021. Contains 348048 sequences. (Running on oeis4.)