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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

%I #10 Oct 20 2018 06:04:59

%S 48,260,1408,7632,41344,224064,1213952,6578432,35643392,193143808,

%T 1046528000,5670785024,30726979584,166497435648,902168182784,

%U 4888469241856,26488322654208,143528684683264,777716068515840

%N 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.

%H R. H. Hardin, <a href="/A235904/b235904.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) + 20*a(n-2) - 8*a(n-3).

%F 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

%e Some solutions for n=4:

%e ..2..1....0..0....2..0....1..2....0..1....2..0....2..2....2..1....2..2....2..2

%e ..0..0....1..0....1..2....0..2....2..2....1..0....0..2....0..2....2..1....2..1

%e ..0..1....2..0....0..2....1..2....1..0....0..2....1..2....0..1....2..0....1..1

%e ..2..2....2..2....0..0....0..0....2..0....2..2....0..0....2..2....0..0....2..1

%e ..1..2....0..1....1..2....2..1....2..2....0..2....0..1....0..1....1..2....0..2

%Y Column 1 of A235911.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 16 2014

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Last modified April 16 17:00 EDT 2024. Contains 371749 sequences. (Running on oeis4.)