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Equals one maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX2 array
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%I #5 Dec 15 2012 05:44:39

%S 2,4,22,74,250,848,2851,9535,31888,106775,357028,1193927,3992279,

%T 13348541,44630321,149215567,498878032,1667898396,5576255601,

%U 18642932177,62328230082,208379401186,696665636518,2329130179184,7786871066006

%N Equals one maps: number of nX2 binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal, vertical and antidiagonal neighbors in a random 0..1 nX2 array

%C Column 2 of A220461

%H R. H. Hardin, <a href="/A220456/b220456.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) -11*a(n-2) +10*a(n-3) -11*a(n-4) +7*a(n-5) -22*a(n-6) +61*a(n-7) -101*a(n-8) +159*a(n-9) -166*a(n-10) +159*a(n-11) -137*a(n-12) +189*a(n-13) -246*a(n-14) +239*a(n-15) -183*a(n-16) +96*a(n-17) -60*a(n-18) +193*a(n-19) -214*a(n-20) +187*a(n-21) -199*a(n-22) +29*a(n-23) -105*a(n-24) +20*a(n-25) -37*a(n-26) +13*a(n-27) -8*a(n-28) +4*a(n-29) for n>34

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 15 2012