login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..2 nX3 array
1

%I #5 Jan 04 2013 04:37:05

%S 2,27,274,2648,23765,203122,1686374,13787513,111630017,898826748,

%T 7215684025,57832318493,463108937837,3706758773474,29661932054299,

%U 237327986894765,1898757328855273,15190598160183104,121526907452205194

%N Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, vertical and antidiagonal neighbors in a random 0..2 nX3 array

%C Column 3 of A221188

%H R. H. Hardin, <a href="/A221186/b221186.txt">Table of n, a(n) for n = 1..190</a>

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 04 2013