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A231391 Number of (n+1) X (3+1) 0..2 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.

%I A231391 #6 Sep 04 2022 08:41:55
%S A231391 14,38,100,272,740,2061,5834,16521,46969,133864,382377,1093837,
%T A231391 3133209,8984580,25782696,74034161,212690121,611260183,1757248511,
%U A231391 5052897615,14532031920,41799692849,120245136990,345938696990,995313138719
%N A231391 Number of (n+1) X (3+1) 0..2 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.
%C A231391 Column 3 of A231396.
%H A231391 R. H. Hardin, <a href="/A231391/b231391.txt">Table of n, a(n) for n = 1..210</a>
%F A231391 Empirical: a(n) = 4*a(n-1) -8*a(n-3) -8*a(n-4) +7*a(n-5) +12*a(n-6) +23*a(n-7) -42*a(n-8) -16*a(n-9) +81*a(n-10) -14*a(n-11) -52*a(n-12) +15*a(n-13) -2*a(n-14) -17*a(n-15) +4*a(n-16) +10*a(n-17) +4*a(n-18).
%e A231391 Some solutions for n=4
%e A231391 ..0..0..1..1....0..0..1..1....0..0..0..1....0..0..0..0....0..0..0..1
%e A231391 ..0..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1
%e A231391 ..0..1..1..1....0..1..1..1....1..1..1..1....0..1..1..1....0..0..1..1
%e A231391 ..0..0..1..1....1..0..1..1....1..1..2..2....1..0..0..0....1..1..0..0
%e A231391 ..0..0..1..1....0..1..0..0....1..2..2..2....1..1..0..0....1..1..0..0
%Y A231391 Cf. A231396.
%K A231391 nonn
%O A231391 1,1
%A A231391 _R. H. Hardin_, Nov 08 2013