A069441 Half the number of n X 3 binary arrays with no path of adjacent 1's or adjacent 0's from top row to bottom row.

0, 4, 84, 1074, 11058, 102448, 896026, 7578952, 62820362, 514178822, 4174954460, 33725176208, 271523097884, 2181288088576, 17498432045552, 140241880816930, 1123280018219562, 8993350007112124, 71984384316723134, 576073752326317448, 4609640266662591130

Offset: 1

Author

R. H. Hardin, Mar 22 2002

Keywords

• nonn
• easy

Crossrefs

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.

Formula

a(n) = 2^(3*n-1) - A069378(n) + A069403(n). - Sean A. Irvine, Aug 23 2024

Extensions

More terms from Sean A. Irvine, Aug 23 2024