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A237160 Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the minimum minus the upper median minus the lower median of every 2 X 2 subblock equal. 1
81, 245, 777, 2597, 8961, 31837, 115561, 427093, 1600465, 6064925, 23183481, 89239333, 345404641, 1342911981, 5240253833, 20510674037, 80485531761, 316523691581, 1247135002521, 4921936192325, 19452979579137, 76982463799693 (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) = 7*a(n-1) + 2*a(n-2) - 92*a(n-3) + 80*a(n-4) + 376*a(n-5) - 360*a(n-6) - 600*a(n-7) + 400*a(n-8) + 320*a(n-9).

Empirical g.f.: x*(81 - 322*x - 1100*x^2 + 4120*x^3 + 5288*x^4 - 14656*x^5 - 11416*x^6 + 15792*x^7 + 9664*x^8) / ((1 - 4*x)*(1 - 2*x^2)*(1 - 3*x - 2*x^2)*(1 - 10*x^2 + 20*x^4)). - Colin Barker, Oct 21 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Column 1 of A237167.

Sequence in context: A237167 A236893 A044986 * A236886 A206142 A225027

Adjacent sequences:  A237157 A237158 A237159 * A237161 A237162 A237163

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 04 2014

STATUS

approved

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Last modified May 23 16:39 EDT 2022. Contains 353977 sequences. (Running on oeis4.)