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A303011 Number of nX3 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1
4, 20, 68, 308, 1320, 5220, 22652, 95220, 390580, 1662564, 6961252, 28957492, 122178532, 511463444, 2138409476, 8987766644, 37641997156, 157656704660, 661559870852, 2771791087028, 11615849382436, 48710299475156 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A303016.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +4*a(n-2) +30*a(n-3) -88*a(n-4) -52*a(n-5) -84*a(n-6) -200*a(n-7) -80*a(n-8) -112*a(n-9) -96*a(n-10)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303016.

Sequence in context: A123613 A006740 A291526 * A197426 A061981 A054611

Adjacent sequences:  A303008 A303009 A303010 * A303012 A303013 A303014

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 17 2018

STATUS

approved

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Last modified April 7 10:26 EDT 2020. Contains 333300 sequences. (Running on oeis4.)