A207748 Number of nX4 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 0 vertically

9, 81, 289, 900, 3249, 11449, 42436, 157609, 597529, 2280100, 8791225, 34093921, 133033156, 521345889, 2051093521, 8093881156, 32021313025, 126943276681, 504097160004, 2004526450969, 7979839669321, 31795772223076, 126783929266569

Offset

1,1

Comments

Column 4 of A207752

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -15*a(n-2) -70*a(n-3) +208*a(n-4) +148*a(n-5) -795*a(n-6) +15*a(n-7) +1267*a(n-8) -318*a(n-9) -840*a(n-10) +280*a(n-11) +176*a(n-12) -64*a(n-13) for n>14

Example

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

Crossrefs

Sequence in context: A207119 A207399 A207904 * A208035 A207124 A207854

Adjacent sequences: A207745 A207746 A207747 * A207749 A207750 A207751

Keyword

nonn

Author

R. H. Hardin Feb 19 2012

Status

approved