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A275144 Number of 4 X n 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2. 1
14, 216, 400, 1088, 2320, 6464, 17872, 49792, 139664, 392448, 1102416, 3095808, 8693584, 24414784, 68567696, 192568832, 540817040, 1518847552, 4265581328, 11979603776, 33643929040, 94486756224, 265359817104, 745245528576 (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) = 5*a(n-1) - 9*a(n-2) + 10*a(n-3) - 6*a(n-4) + a(n-5) for n>9.

Empirical g.f.: 2*x*(7 + 73*x - 277*x^2 + 446*x^3 - 798*x^4 + 969*x^5 - 1132*x^6 + 768*x^7 - 128*x^8) / ((1 - x)*(1 - 4*x + 5*x^2 - 5*x^3 + x^4)). - Colin Barker, Feb 01 2019

EXAMPLE

Some solutions for n=5:

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

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

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

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

CROSSREFS

Row 4 of A275142.

Sequence in context: A331494 A208430 A275224 * A275354 A121972 A240781

Adjacent sequences:  A275141 A275142 A275143 * A275145 A275146 A275147

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 17 2016

STATUS

approved

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Last modified September 23 19:48 EDT 2021. Contains 347617 sequences. (Running on oeis4.)