A069448 Half the number of 3 X n binary arrays with no path of adjacent 1's or adjacent 0's from top to bottom or side to side.

3, 35, 269, 1723, 10123, 56757, 309755, 1663515, 8846821, 46767491, 246319875, 1294402053, 6792548971, 35614277883, 186632524741, 977711862035, 5120933346419

Offset

2,1

Links

Table of n, a(n) for n=2..18.

Crossrefs

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: A019273 A271209 A202883 * A339516 A121078 A289950

Adjacent sequences: A069445 A069446 A069447 * A069449 A069450 A069451

Keyword

nonn

Author

R. H. Hardin, Mar 22 2002

Status

approved