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A230677 Number of 3Xn 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value 2-x(i,j).

%I A230677 #6 Jun 02 2025 08:45:25
%S A230677 0,81,1173,18915,340563,6081561,108108231,1923264723,34219066161,
%T A230677 608809697883,10831633601715,192711252863829,3428626492612815,
%U A230677 61000479835023903,1085291316379044081,19308983258977687575
%N A230677 Number of 3Xn 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value 2-x(i,j).
%C A230677 Row 3 of A230675
%H A230677 R. H. Hardin, <a href="/A230677/b230677.txt">Table of n, a(n) for n = 1..210</a>
%F A230677 Empirical: a(n) = 13*a(n-1) +65*a(n-2) +312*a(n-3) +829*a(n-4) +559*a(n-5) -458*a(n-6) -2767*a(n-7) -2801*a(n-8) -1031*a(n-9) -485*a(n-10) -743*a(n-11) -272*a(n-12) +332*a(n-13) +172*a(n-14) -24*a(n-15) for n>16
%e A230677 Some solutions for n=3
%e A230677 ..0..2..0....2..2..0....2..0..2....0..2..0....2..0..2....0..2..1....0..0..0
%e A230677 ..0..0..2....0..0..2....0..2..2....0..1..1....2..2..0....2..1..1....2..2..0
%e A230677 ..0..2..2....2..1..1....2..0..2....2..0..2....0..2..0....1..0..2....0..0..0
%K A230677 nonn
%O A230677 1,2
%A A230677 _R. H. Hardin_, Oct 27 2013