A220330 - OEIS

%I #4 Dec 10 2012 18:15:06

%S 1,12,92,572,4062,29467,213225,1540686,11163495,80656708,581473349,

%T 4190483128,30199355040,217538559602,1566825952174,11283025994195,

%U 81236036737903,584831754731217,4210022381269251,30304818855812080

%N Equals two maps: number of 3Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..1 3Xn array

%C Row 3 of A220328

%H R. H. Hardin, <a href="/A220330/b220330.txt">Table of n, a(n) for n = 1..22</a>

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Dec 10 2012