A284224 - OEIS

%I #6 Apr 05 2020 22:47:27

%S 4,19,70,499,3214,22729,163708,1209005,9018250,67956917,515031078,

%T 3926103884,30049105764,230871573750,1779036977175,13746097605518,

%U 106448904000193,826010061981163,6420762665883318,49989175241774203

%N Number of 3 X n 0..1 arrays with the number of 1's horizontally or antidiagonally adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero.

%C Row 3 of A284222.

%H R. H. Hardin, <a href="/A284224/b284224.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4

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

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

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

%Y Cf. A284222.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 23 2017