cp's OEIS Frontend

A218837 Unmatched value maps: number of n X 3 binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..1 n X 3 array.

%I A218837 #8 Mar 10 2018 07:15:12
%S A218837 4,20,93,436,2043,9573,44857,210190,984904,4615043,21625074,101330329,
%T A218837 474811581,2224862385,10425214612,48850257184,228901534957,
%U A218837 1072582125992,5025883366023,23550181377025,110350957732161,517080258425742
%N A218837 Unmatched value maps: number of n X 3 binary arrays indicating the locations of corresponding elements not equal to any horizontal or antidiagonal neighbor in a random 0..1 n X 3 array.
%C A218837 Column 3 of A218842.
%H A218837 R. H. Hardin, <a href="/A218837/b218837.txt">Table of n, a(n) for n = 1..210</a>
%F A218837 Empirical: a(n) = 4*a(n-1) + 3*a(n-2) + a(n-3).
%F A218837 Empirical g.f.: x*(2 + x)^2 / (1 - 4*x - 3*x^2 - x^3). - _Colin Barker_, Mar 10 2018
%e A218837 Some solutions for n=3:
%e A218837 ..1..1..0....1..0..0....1..0..0....1..1..0....1..0..0....0..0..0....0..0..0
%e A218837 ..0..0..0....1..0..0....0..0..1....0..0..1....1..0..1....1..0..0....0..0..0
%e A218837 ..0..1..1....1..0..1....0..0..0....0..0..1....1..1..1....1..0..1....1..0..0
%Y A218837 Cf. A218842.
%K A218837 nonn
%O A218837 1,1
%A A218837 _R. H. Hardin_, Nov 07 2012