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A219143 Unchanging value maps: number of 2 X n binary arrays indicating the locations of corresponding elements unequal to no horizontal, diagonal or antidiagonal neighbor in a random 0..2 2 X n array. 2

%I

%S 1,6,18,39,96,225,543,1293,3096,7392,17673,42228,100929,241197,576441,

%T 1377606,3292314,7868187,18803964,44939013,107398431,256668285,

%U 613403916,1465955712,3503443917,8372776200,20009848437,47820940581,114285841233

%N Unchanging value maps: number of 2 X n binary arrays indicating the locations of corresponding elements unequal to no horizontal, diagonal or antidiagonal neighbor in a random 0..2 2 X n array.

%C Row 2 of A219142.

%H R. H. Hardin, <a href="/A219143/b219143.txt">Table of n, a(n) for n = 1..210</a>

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

%F Empirical g.f.: x*(1 + 4*x + 5*x^2 - 2*x^3 + 4*x^4) / (1 - 2*x - x^2 + x^3 - 2*x^4). - _Colin Barker_, Mar 11 2018

%e Some solutions for n=3:

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

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

%Y Cf. A219142.

%K nonn

%O 1,2

%A _R. H. Hardin_, Nov 12 2012

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Last modified September 20 11:42 EDT 2021. Contains 347584 sequences. (Running on oeis4.)