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A283858 Number of 2 X n 0..1 arrays with no 1 equal to more than three of its horizontal, diagonal and antidiagonal neighbors. 1
4, 16, 61, 233, 896, 3444, 13225, 50789, 195076, 749256, 2877717, 11052673, 42450984, 163045180, 626221537, 2405182717, 9237791852, 35480380112, 136272540429, 523393640665, 2010242874320, 7720912327300, 29654370583449 (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) = 3*a(n-1) + a(n-2) + 7*a(n-3) + 6*a(n-4).

Empirical g.f.: x*(4 + 4*x + 9*x^2 + 6*x^3) / (1 - 3*x - x^2 - 7*x^3 - 6*x^4). - Colin Barker, Feb 22 2019

EXAMPLE

Some solutions for n=4:

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

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

CROSSREFS

Row 2 of A283857.

Sequence in context: A103820 A206570 A206790 * A283409 A192468 A276042

Adjacent sequences:  A283855 A283856 A283857 * A283859 A283860 A283861

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 17 2017

STATUS

approved

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Last modified January 16 14:59 EST 2022. Contains 350376 sequences. (Running on oeis4.)