cp's OEIS Frontend

A230170 Number of n X 2 0..2 arrays x(i,j) with each element horizontally, vertically, diagonally or antidiagonally next to at least one element with value 2-x(i,j).

%I A230170 #7 Sep 21 2018 11:39:26
%S A230170 3,27,193,1407,10211,73417,530771,3841171,27770777,200748959,
%T A230170 1451396131,10493696945,75868350707,548518150083,3965728577777,
%U A230170 28671821546207,207294285260867,1498715914818009,10835559670997043,78339967436748115
%N A230170 Number of n X 2 0..2 arrays x(i,j) with each element horizontally, vertically, diagonally or antidiagonally next to at least one element with value 2-x(i,j).
%H A230170 R. H. Hardin, <a href="/A230170/b230170.txt">Table of n, a(n) for n = 1..210</a>
%F A230170 Empirical: a(n) = 6*a(n-1) - 2*a(n-2) + 67*a(n-3) + 62*a(n-4) + 160*a(n-5) + 40*a(n-6) + 16*a(n-7).
%F A230170 Empirical g.f.: x*(1 - x + 11*x^2 - 2*x^3)*(3 + 12*x + 16*x^2 - 8*x^3) / (1 - 6*x + 2*x^2 - 67*x^3 - 62*x^4 - 160*x^5 - 40*x^6 - 16*x^7). - _Colin Barker_, Sep 21 2018
%e A230170 Some solutions for n=3:
%e A230170 ..2..0....0..0....1..0....1..1....2..2....1..2....1..2....2..0....2..1....0..2
%e A230170 ..2..1....2..1....1..2....0..1....0..2....1..0....0..1....0..1....1..0....2..1
%e A230170 ..0..1....1..1....1..0....2..1....2..0....2..0....1..1....2..1....1..2....1..1
%Y A230170 Column 2 of A230176.
%K A230170 nonn
%O A230170 1,1
%A A230170 _R. H. Hardin_, Oct 11 2013