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A209651
Number of 4Xn 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 0 1 vertically
2
8, 64, 216, 630, 2156, 7128, 24990, 87136, 311040, 1112150, 4018716, 14563584, 53065350, 193861408, 710502760, 2609417910, 9603620076, 35401092264, 130688898510, 483039609408, 1787282764624, 6619084515926, 24532925650268
OFFSET
1,1
COMMENTS
Row 4 of A209650
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) -11*a(n-2) -108*a(n-3) +272*a(n-4) +480*a(n-5) -1754*a(n-6) -942*a(n-7) +5482*a(n-8) +552*a(n-9) -9304*a(n-10) +888*a(n-11) +8539*a(n-12) -1755*a(n-13) -3871*a(n-14) +1092*a(n-15) +648*a(n-16) -216*a(n-17) for n>18
EXAMPLE
Some solutions for n=4
..1..1..1..1....1..0..1..0....1..0..1..0....1..1..0..1....1..0..1..1
..1..1..1..1....1..0..1..0....0..0..0..0....0..0..0..0....1..1..0..1
..1..1..1..1....1..0..1..0....0..0..0..0....0..0..0..0....0..1..0..1
..1..1..1..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
CROSSREFS
Sequence in context: A016743 A340695 A086114 * A207071 A117219 A267783
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 11 2012
STATUS
approved