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 A233951 Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having the sum of the squares of the edge differences equal to 10, and no two adjacent values equal. 1

%I #8 Oct 12 2018 10:49:50

%S 80,380,1776,8336,39084,183304,859628,4031428,18906220,88664800,

%T 415812536,1950042036,9145139904,42888093244,201132903028,

%U 943255846788,4423600410160,20745421993920,97290101680796,456262778740936

%N Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having the sum of the squares of the edge differences equal to 10, and no two adjacent values equal.

%H R. H. Hardin, <a href="/A233951/b233951.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) + 5*a(n-2) - 7*a(n-3) - 6*a(n-4).

%F Empirical g.f.: 4*x*(4 + 3*x)*(5 - 9*x^2) / (1 - 4*x - 5*x^2 + 7*x^3 + 6*x^4). - _Colin Barker_, Oct 12 2018

%e Some solutions for n=5:

%e ..0..1....5..4....1..3....5..4....4..5....4..2....3..2....2..1....1..0....2..1

%e ..2..3....4..2....0..1....3..5....2..4....3..1....5..3....1..3....3..2....4..2

%e ..3..1....2..3....2..0....4..3....4..3....2..0....3..2....3..4....5..3....5..3

%e ..4..3....4..5....3..2....3..1....2..4....3..2....2..0....1..3....4..2....4..5

%e ..2..1....2..3....2..4....4..3....1..2....1..3....3..2....0..1....2..3....2..4

%e ..1..3....3..5....4..3....2..4....2..0....3..2....5..3....2..0....4..5....1..3

%Y Column 1 of A233958.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 18 2013

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Last modified October 3 20:04 EDT 2023. Contains 365870 sequences. (Running on oeis4.)