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A235904 Number of (n+1) X (1+1) 0..2 arrays with the minimum plus the maximum unequal to the lower median plus the upper median in every 2 X 2 subblock. 1
48, 260, 1408, 7632, 41344, 224064, 1213952, 6578432, 35643392, 193143808, 1046528000, 5670785024, 30726979584, 166497435648, 902168182784, 4888469241856, 26488322654208, 143528684683264, 777716068515840 (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) = 2*a(n-1) + 20*a(n-2) - 8*a(n-3).

Empirical g.f.: 4*x*(12 + 41*x - 18*x^2) / (1 - 2*x - 20*x^2 + 8*x^3). - Colin Barker, Oct 20 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 1 of A235911.

Sequence in context: A206047 A223434 A235911 * A275406 A205469 A115056

Adjacent sequences:  A235901 A235902 A235903 * A235905 A235906 A235907

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 16 2014

STATUS

approved

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Last modified October 25 03:56 EDT 2021. Contains 348237 sequences. (Running on oeis4.)