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A283573 Number of 2Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element. 1
0, 4, 26, 72, 282, 908, 2832, 8856, 26750, 80088, 237190, 695272, 2024064, 5853676, 16835874, 48194664, 137385394, 390201476, 1104636144, 3118021376, 8778028806, 24653647608, 69091665822, 193246772832, 539525988960, 1503796131028 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 2 of A283572.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +5*a(n-2) +2*a(n-3) -17*a(n-4) -24*a(n-5) -16*a(n-6).

Empirical: G.f.: 2*x^2*(2+9*x)/(-1+x+3*x^2+4*x^3)^2 . - R. J. Mathar, Mar 11 2017

EXAMPLE

Some solutions for n=4

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

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

CROSSREFS

Cf. A283572.

Sequence in context: A273981 A099442 A014450 * A200058 A142962 A247194

Adjacent sequences:  A283570 A283571 A283572 * A283574 A283575 A283576

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 11 2017

STATUS

approved

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Last modified August 3 18:48 EDT 2021. Contains 346440 sequences. (Running on oeis4.)