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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
0, 4, 84, 1074, 11058, 102448, 896026, 7578952, 62820362, 514178822, 4174954460, 33725176208, 271523097884, 2181288088576, 17498432045552, 140241880816930, 1123280018219562, 8993350007112124, 71984384316723134, 576073752326317448, 4609640266662591130
OFFSET
1,2
FORMULA
a(n) = 2^(3*n-1) - A069378(n) + A069403(n). - Sean A. Irvine, Aug 23 2024
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.
Sequence in context: A172138 A282588 A178208 * A203095 A006344 A203244
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Mar 22 2002
EXTENSIONS
More terms from Sean A. Irvine, Aug 23 2024
STATUS
approved