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A281982 Number of n X 2 0..1 arrays with no element unequal to more than four of its king-move neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1
0, 0, 2, 16, 88, 432, 2008, 8992, 39200, 167552, 705440, 2934784, 12091264, 49416448, 200598912, 809606656, 3251253760, 12999782400, 51779385856, 205542608896, 813446920192, 3210502631424, 12640023828480, 49653803819008 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) - 20*a(n-2) + 24*a(n-3) - 36*a(n-4) + 16*a(n-5) - 16*a(n-6).

Empirical g.f.: 2*x^3 / (1 - 4*x + 2*x^2 - 4*x^3)^2. - Colin Barker, Feb 20 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 2 of A281988.

Sequence in context: A220505 A069440 A000431 * A207595 A253487 A207019

Adjacent sequences:  A281979 A281980 A281981 * A281983 A281984 A281985

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 04 2017

STATUS

approved

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Last modified March 18 13:47 EDT 2019. Contains 321289 sequences. (Running on oeis4.)