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%I #4 Jan 04 2018 22:00:42
%S 1,29,145,523,2717,14462,68919,332306,1652441,8140067,39816114,
%T 195543171,961617387,4722204339,23186542778,113898106759,559470061363,
%U 2747805117373,13496167444555,66289849507630,325594360281088
%N Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 4 neighboring 1s.
%C Row 3 of A297720.
%H R. H. Hardin, <a href="/A297722/b297722.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) -5*a(n-2) +6*a(n-3) -17*a(n-4) -168*a(n-5) +284*a(n-6) +316*a(n-7) -636*a(n-8) +40*a(n-9) +732*a(n-10) -863*a(n-11) -414*a(n-12) +846*a(n-13) +17*a(n-14) -297*a(n-15) +188*a(n-16) +50*a(n-17) -52*a(n-18)
%e Some solutions for n=7
%e ..0..1..0..0..0..0..0. .0..0..0..1..0..1..0. .1..0..1..1..1..1..1
%e ..0..1..1..0..1..1..0. .0..0..0..0..1..0..1. .1..1..0..0..0..0..0
%e ..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .1..1..0..0..1..1..1
%Y Cf. A297720.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 04 2018