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A188708
Number of 4 X n binary arrays without the pattern 0 0 diagonally or vertically.
1
8, 49, 304, 1876, 11556, 71152, 438048, 2696784, 16602304, 102209216, 629233216, 3873764352, 23848153088, 146816985344, 903853103104, 5564413613056, 34256339608576, 210893165924352, 1298326906544128, 7992922619695104
OFFSET
1,1
COMMENTS
Row 4 of A188706.
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) - 12*a(n-2) + 4*a(n-3).
Empirical g.f.: x*(8 - 15*x + 8*x^2) / (1 - 8*x + 12*x^2 - 4*x^3). - Colin Barker, Apr 28 2018
EXAMPLE
Some solutions for 4 X 3:
1 0 0 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 0 1 1
0 1 1 0 0 0 1 1 0 1 1 1 1 1 0 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 0 0 1 1 1
1 1 0 1 1 0 0 1 1 1 0 0 1 1 1 1 1 1 0 0 0
CROSSREFS
Cf. A188706.
Sequence in context: A097204 A037539 A037483 * A317752 A273497 A024106
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 08 2011
STATUS
approved