A220580 - OEIS

%I #4 Dec 16 2012 12:11:23

%S 1,8,21,115,371,1504,5240,19904,71787,266591,973703,3590009,13161398,

%T 48409054,177699822,653013280,2398088376,8809799868,32356803616,

%U 118855121770,436550962678,1603501078153,5889674104016,21633105877502

%N Equals one maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 2Xn array

%C Row 2 of A220579

%H R. H. Hardin, <a href="/A220580/b220580.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=3

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Dec 16 2012