cp's OEIS Frontend

A232131 Number of (n+1) X (2+1) 0..2 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with values 0..2 introduced in row major order.

%I A232131 #7 Oct 03 2018 08:41:36
%S A232131 36,728,14752,298912,6056640,122721280,2486611712,50384397824,
%T A232131 1020902270976,20685797427200,419141212008448,8492752393142272,
%U A232131 172082441775661056,3486780892303556608,70650095765044723712
%N A232131 Number of (n+1) X (2+1) 0..2 arrays with no element equal to a strict majority of its horizontal and antidiagonal neighbors, with values 0..2 introduced in row major order.
%H A232131 R. H. Hardin, <a href="/A232131/b232131.txt">Table of n, a(n) for n = 1..210</a>
%F A232131 Empirical: a(n) = 22*a(n-1) - 36*a(n-2) + 16*a(n-3).
%F A232131 Empirical g.f.: 4*x*(9 - 16*x + 8*x^2) / (1 - 22*x + 36*x^2 - 16*x^3). - _Colin Barker_, Oct 03 2018
%e A232131 Some solutions for n=4:
%e A232131 ..0..1..0....0..1..0....0..1..0....0..1..0....0..1..0....0..1..0....0..1..0
%e A232131 ..1..0..0....0..1..0....1..0..2....0..0..2....0..1..0....0..1..1....1..0..1
%e A232131 ..1..2..1....1..2..0....0..1..0....2..2..1....0..0..2....1..0..0....2..1..2
%e A232131 ..0..1..2....0..2..0....2..0..1....0..2..1....1..2..1....1..2..2....0..0..1
%e A232131 ..2..0..2....2..1..0....0..1..2....1..0..1....0..1..0....1..0..2....1..0..2
%Y A232131 Column 2 of A232137.
%K A232131 nonn
%O A232131 1,1
%A A232131 _R. H. Hardin_, Nov 19 2013