2,1
Cf. 2 X n A000225, vertical path of 1 A069361-A069395, vertical paths of 0+1 A069396-A069416, vertical path of 1 not 0 A069417-A069428, no vertical paths A069429-A069447, no horizontal or vertical paths A069448-A069452.
Sequence in context: A048291 A015089 A179565 * A140031 A066413 A037067
Adjacent sequences: A069446 A069447 A069448 * A069450 A069451 A069452
nonn
R. H. Hardin (rhhardin(AT)att.net), Mar 22 2002.