A220381 - OEIS

%I #7 Jul 31 2018 08:53:34

%S 4,25,136,753,4160,22989,127037,702009,3879313,21437148,118462034,

%T 654623158,3617458391,19990134860,110465815644,610435923087,

%U 3373279000591,18640795512630,103009344107857,569231338133692

%N Majority value maps: number of n X 3 binary arrays indicating the locations of corresponding elements equal to at least half of their horizontal and antidiagonal neighbors in a random 0..1 n X 3 array.

%C Column 3 of A220386.

%H R. H. Hardin, <a href="/A220381/b220381.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) + 8*a(n-2) + 3*a(n-3) - 3*a(n-4) - 2*a(n-5).

%F Empirical g.f.: x*(4 + 9*x + 4*x^2 - 3*x^3 - 3*x^4) / (1 - 4*x - 8*x^2 - 3*x^3 + 3*x^4 + 2*x^5). - _Colin Barker_, Jul 31 2018

%e Some solutions for n=3:

%e ..0..0..1....0..0..1....0..0..1....1..1..1....0..0..1....1..1..1....1..1..0

%e ..0..1..0....0..1..1....1..1..0....1..1..1....0..1..1....1..0..0....1..0..0

%e ..1..0..0....1..1..0....0..0..1....1..0..0....0..1..1....0..0..1....0..0..0

%Y Cf. A220386.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 13 2012