%I #4 Jan 05 2018 16:02:28

%S 1,11,66,174,452,2223,9733,32213,109959,444222,1741686,6270922,

%T 22908011,87743411,332882553,1231723189,4581917598,17276990320,

%U 64938750220,242324446545,905905664957,3399845574813,12746035541887,47685495021184

%N Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 3 or 4 neighboring 1s.

%C Row 3 of A297749.

%H R. H. Hardin, <a href="/A297751/b297751.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +a(n-2) +14*a(n-3) +49*a(n-4) -41*a(n-5) -129*a(n-6) -172*a(n-7) -96*a(n-8) +68*a(n-9) +88*a(n-10) +150*a(n-11) +121*a(n-12) +a(n-13) +15*a(n-14) -32*a(n-15) -7*a(n-16) -14*a(n-17) -3*a(n-18) +2*a(n-19)

%e Some solutions for n=7

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

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

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

%Y Cf. A297749.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 05 2018