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A231518 Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.

%I A231518 #6 Jul 23 2025 06:33:29
%S A231518 4,34,153,776,3861,18721,91993,453274,2223662,10915727,53635324,
%T A231518 263420767,1293604417,6353594215,31205396110,153258629442,
%U A231518 752708346275,3696838244354,18156489259107,89173024237567,437961215793703
%N A231518 Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors.
%C A231518 Column 3 of A231523
%H A231518 R. H. Hardin, <a href="/A231518/b231518.txt">Table of n, a(n) for n = 1..210</a>
%F A231518 Empirical: a(n) = 4*a(n-1) -2*a(n-2) +43*a(n-3) -50*a(n-4) +33*a(n-5) -307*a(n-6) +115*a(n-7) -66*a(n-8) +490*a(n-9) +60*a(n-10) -144*a(n-11) +32*a(n-12) -192*a(n-13) for n>14
%e A231518 Some solutions for n=7
%e A231518 ..0..1..0....0..0..1....1..0..1....0..0..1....1..0..0....1..0..0....1..0..0
%e A231518 ..1..0..0....0..1..1....0..0..0....0..0..1....0..0..0....1..1..0....0..1..1
%e A231518 ..1..0..0....0..0..0....1..0..0....0..0..0....1..1..0....1..0..0....1..0..0
%e A231518 ..0..0..0....0..0..1....1..0..0....1..0..0....0..0..1....0..0..1....0..0..1
%e A231518 ..0..0..0....1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....1..1..0
%e A231518 ..0..0..0....0..0..0....0..0..1....0..0..0....0..0..1....1..0..0....1..0..0
%e A231518 ..0..0..1....0..1..0....1..0..0....1..1..1....1..1..1....0..0..1....0..0..0
%K A231518 nonn
%O A231518 1,1
%A A231518 _R. H. Hardin_, Nov 10 2013