%I

%S 2,16,496,58640,26536192,45851039232,302758305892480,

%T 7638804476736307712,736437724731312162567680,

%U 271287639195997221896855543808,381862430868672544566361613406502912

%N Number of n X n binary matrices with every 1 having at most 3 adjacent 1's.

%Y No adjacent 1's A006506, one adjacent 1 A067968.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 10 2002