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%I #4 Dec 25 2012 10:59:45
%S 4,52,673,9107,123958,1686304,22931365,311813067,4239917031,
%T 57652874111,783943412638,10659785895199,144948006719997,
%U 1970951840091756,26800307525626867,364421123267042408,4955269821323438717
%N Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 nX4 array
%C Column 4 of A220935
%H R. H. Hardin, <a href="/A220933/b220933.txt">Table of n, a(n) for n = 1..156</a>
%F Empirical: a(n) = 28*a(n-1) -296*a(n-2) +1804*a(n-3) -7384*a(n-4) +21847*a(n-5) -48816*a(n-6) +85558*a(n-7) -123954*a(n-8) +160701*a(n-9) -200185*a(n-10) +236867*a(n-11) -248056*a(n-12) +226758*a(n-13) -197374*a(n-14) +171224*a(n-15) -136118*a(n-16) +103073*a(n-17) -90758*a(n-18) +83397*a(n-19) -61987*a(n-20) +38070*a(n-21) -26150*a(n-22) +15689*a(n-23) -3389*a(n-24) -92*a(n-25) -312*a(n-26) +112*a(n-27) -16*a(n-28)
%e Some solutions for n=3
%e ..0..0..0..0....0..0..1..0....0..1..0..0....0..1..1..0....0..1..1..0
%e ..0..0..0..0....0..0..0..0....1..0..0..1....0..0..0..1....0..0..1..0
%e ..0..0..0..0....0..0..1..0....1..0..1..0....1..0..1..0....0..0..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Dec 25 2012
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