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A206688 Number of nX4 0..3 arrays with no element equal to another within two positions in the same row or column, and new values 0..3 introduced in row major order 1
2, 36, 176, 916, 4704, 24492, 127008, 660888, 3436488, 17884080, 93059016, 484334480, 2520695968, 13119605656, 68284077520, 355405952496, 1849822022856, 9628019156288, 50112266984832, 260826450827576, 1357560738338768 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A206692

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-1) -8*a(n-2) -48*a(n-3) +48*a(n-4) +140*a(n-5) +67*a(n-6) -968*a(n-7) +1564*a(n-8) -586*a(n-9) -1008*a(n-10) -32*a(n-11) +1304*a(n-12) +80*a(n-13) -512*a(n-14) for n>15

EXAMPLE

Some solutions for n=4

..0..1..2..3....0..1..2..3....0..1..2..3....0..1..2..3....0..1..2..3

..2..3..0..2....3..0..1..2....1..0..3..1....2..3..1..0....2..3..0..1

..3..2..1..0....1..2..3..1....2..3..1..0....3..2..0..1....1..0..3..2

..0..1..2..3....0..1..2..0....3..1..0..2....0..1..2..3....0..1..2..3

CROSSREFS

Sequence in context: A227927 A007757 A141217 * A226419 A025531 A099903

Adjacent sequences:  A206685 A206686 A206687 * A206689 A206690 A206691

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 11 2012

STATUS

approved

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Last modified July 23 03:25 EDT 2019. Contains 325230 sequences. (Running on oeis4.)