A208143 Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically

8, 64, 240, 900, 2400, 6400, 14000, 30625, 58800, 112896, 197568, 345744, 564480, 921600, 1425600, 2205225, 3267000, 4840000, 6921200, 9897316, 13741728, 19079424, 25836720, 34987225, 46373600, 61465600, 79968000, 104040000

Offset

1,1

Comments

Row 4 of A208142

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
..0..0..0..0....0..0..0..0....1..1..0..1....1..0..0..0....1..1..1..1
..1..0..0..0....0..1..0..0....0..0..0..0....0..1..0..0....1..1..1..1
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..1..1..1
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..1..1..1

Crossrefs

Sequence in context: A208288 A362853 A045825 * A189265 A167239 A236554

Adjacent sequences: A208140 A208141 A208142 * A208144 A208145 A208146

Keyword

nonn

Author

R. H. Hardin Feb 23 2012

Status

approved