cp's OEIS Frontend

A280156 Number of nX3 0..1 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%I A280156 #4 Dec 27 2016 09:18:30
%S A280156 2,8,31,94,305,950,2901,8728,26068,77326,228367,671446,1967328,
%T A280156 5745190,16730555,48594066,140815777,407186706,1175159395,3385527188,
%U A280156 9737463217,27964574958,80197812317,229694924100,657073271390,1877519404364
%N A280156 Number of nX3 0..1 arrays with no element unequal to a strict majority of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
%C A280156 Column 3 of A280161.
%H A280156 R. H. Hardin, <a href="/A280156/b280156.txt">Table of n, a(n) for n = 1..210</a>
%F A280156 Empirical: a(n) = 6*a(n-1) -7*a(n-2) -18*a(n-3) +45*a(n-4) -22*a(n-5) -38*a(n-6) +74*a(n-7) -39*a(n-8) -2*a(n-9) +4*a(n-10) +2*a(n-11) -8*a(n-12) -4*a(n-13) -a(n-14) for n>19
%e A280156 Some solutions for n=4
%e A280156 ..0..0..0. .0..0..0. .0..1..1. .0..1..1. .0..1..1. .0..0..0. .0..0..1
%e A280156 ..0..0..0. .1..1..0. .0..1..1. .0..0..1. .0..1..1. .0..0..0. .0..0..0
%e A280156 ..0..0..1. .1..1..1. .0..1..1. .0..0..1. .0..0..0. .0..0..0. .1..1..0
%e A280156 ..0..0..0. .1..1..1. .0..0..1. .0..1..1. .1..0..0. .0..0..1. .1..1..0
%Y A280156 Cf. A280161.
%K A280156 nonn
%O A280156 1,1
%A A280156 _R. H. Hardin_, Dec 27 2016