1,1
Table of n, a(n) for n=1..9.
Cf. 2 X n A000079, n X 1 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: A034675 A216343 A184222 * A133791 A323781 A253447
Adjacent sequences: A069428 A069429 A069430 * A069432 A069433 A069434
nonn
R. H. Hardin, Mar 22 2002
approved