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A231741 Number of nX2 0..3 arrays with no element less than a strict majority of its horizontal and vertical neighbors.

%I A231741 #7 Jul 23 2025 06:39:11
%S A231741 4,84,318,1328,6064,26918,116909,511264,2248196,9868600,43259517,
%T A231741 189716276,832295019,3650903623,16013507645,70240174360,308101760364,
%U A231741 1351448959786,5927927566218,26002016887928,114054342072628
%N A231741 Number of nX2 0..3 arrays with no element less than a strict majority of its horizontal and vertical neighbors.
%C A231741 Column 2 of A231746
%H A231741 R. H. Hardin, <a href="/A231741/b231741.txt">Table of n, a(n) for n = 1..210</a>
%F A231741 Empirical: a(n) = 10*a(n-1) -39*a(n-2) +104*a(n-3) -251*a(n-4) +391*a(n-5) -483*a(n-6) +687*a(n-7) -378*a(n-8) +503*a(n-9) -247*a(n-10) -66*a(n-11) -292*a(n-12) -300*a(n-13) -217*a(n-14) -153*a(n-15) -70*a(n-16) -27*a(n-17) -8*a(n-18) -a(n-19) for n>20
%e A231741 Some solutions for n=7
%e A231741 ..0..2....1..2....2..0....0..0....2..1....2..1....1..1....2..0....2..0....0..1
%e A231741 ..0..2....1..1....3..0....2..2....1..1....2..1....0..0....0..0....1..0....0..2
%e A231741 ..0..3....1..1....1..0....2..3....1..1....0..0....0..0....0..0....0..0....0..3
%e A231741 ..0..3....3..3....0..0....0..0....1..1....0..0....1..2....2..2....0..0....0..0
%e A231741 ..0..2....0..0....0..0....0..0....2..2....1..0....1..1....3..3....0..0....0..0
%e A231741 ..0..0....0..0....3..2....1..1....2..2....3..0....3..1....0..0....2..2....0..0
%e A231741 ..3..0....2..0....2..2....1..2....3..3....3..0....0..0....0..0....2..3....3..0
%K A231741 nonn
%O A231741 1,1
%A A231741 _R. H. Hardin_, Nov 13 2013