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A231135 Number of (n+1)X(4+1) black-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.

%I A231135 #6 Jul 23 2025 06:16:32
%S A231135 16,182,2260,27171,336004,4066129,50257244,608468617,7520563372,
%T A231135 91054483047,1125418461348,13625913937795,168414092245220,
%U A231135 2039060342079409,25202456511185596,305136757252909097
%N A231135 Number of (n+1)X(4+1) black-square subarrays of 0..2 arrays with no element equal to a strict majority of its diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.
%C A231135 Column 4 of A231137
%H A231135 R. H. Hardin, <a href="/A231135/b231135.txt">Table of n, a(n) for n = 1..210</a>
%F A231135 Empirical: a(n) = 175*a(n-2) -4017*a(n-4) +34311*a(n-6) -146236*a(n-8) +322472*a(n-10) -291040*a(n-12) +116032*a(n-14) -24064*a(n-16) +1024*a(n-18)
%e A231135 Some solutions for n=4
%e A231135 ..x..0..x..1..x....x..0..x..1..x....x..0..x..1..x....x..0..x..0..x
%e A231135 ..0..x..2..x..0....1..x..0..x..2....2..x..0..x..1....0..x..1..x..2
%e A231135 ..x..1..x..0..x....x..2..x..2..x....x..2..x..0..x....x..2..x..2..x
%e A231135 ..1..x..1..x..1....0..x..1..x..0....1..x..1..x..2....1..x..1..x..1
%e A231135 ..x..2..x..0..x....x..0..x..2..x....x..2..x..1..x....x..2..x..0..x
%K A231135 nonn
%O A231135 1,1
%A A231135 _R. H. Hardin_, Nov 04 2013