A221030 - OEIS

%I #8 Mar 13 2018 16:39:13

%S 4,33,228,1561,10648,72625,495329,3378333,23041525,157152036,

%T 1071837150,7310340394,49859324875,340059715828,2319337668908,

%U 15818772327435,107890093495975,735851811608802,5018791541488065,34230082931837488

%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..2 n X 3 array.

%C Column 3 of A221035.

%H R. H. Hardin, <a href="/A221030/b221030.txt">Table of n, a(n) for n = 1..210</a>

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

%F Empirical g.f.: x*(4 + x - 4*x^2 + 5*x^3 - 3*x^4) / (1 - 8*x + 8*x^2 + x^3 - 5*x^4 + 2*x^5). - _Colin Barker_, Mar 13 2018

%e Some solutions for n=3:

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

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

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

%Y Cf. A221035.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 29 2012