A208117 Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically

40, 1600, 9240, 53361, 175560, 577600, 1432600, 3553225, 7419360, 15492096, 28791840, 53509225, 91408240, 156150016, 250232400, 401000625, 611163000, 931470400, 1363358920, 1995498241, 2824994040, 3999297600, 5505737640

Offset

1,1

Comments

Column 7 of A208118

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16)

Example

Some solutions for n=4
..1..0..1..1..1..0..1....1..1..1..0..1..1..0....1..1..1..1..0..0..1
..0..1..1..1..1..0..1....1..1..1..1..0..0..1....1..0..1..1..1..0..0
..0..0..1..1..0..0..1....1..1..0..0..1..1..0....0..0..1..1..0..0..1
..0..0..1..1..1..0..1....1..1..1..1..0..0..1....0..0..1..1..1..0..0

Crossrefs

Sequence in context: A208107 A207728 A207598 * A207702 A207907 A208038

Adjacent sequences: A208114 A208115 A208116 * A208118 A208119 A208120

Keyword

nonn

Author

R. H. Hardin Feb 23 2012

Status

approved