A203281 Number of nX4 binary arrays with every element neighboring horizontally or vertically both a 0 and a 1

0, 16, 64, 676, 4624, 40000, 311364, 2534464, 20286016, 163430656, 1313337600, 10564961796, 84952429156, 683217964900, 5494298496064, 44185267840000, 355334865707584, 2857591405125136, 22980614709965056, 184809152161922500

Offset

1,2

Comments

Column 4 of A203285

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +17*a(n-2) -58*a(n-3) -104*a(n-4) +17*a(n-5) +793*a(n-6) -726*a(n-7) -349*a(n-8) +499*a(n-9) -6*a(n-10) -28*a(n-11) -293*a(n-12) +54*a(n-13) +117*a(n-14) +70*a(n-15) -17*a(n-16) -47*a(n-17) +2*a(n-18) +4*a(n-19) +3*a(n-20) -a(n-21)

Example

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

Crossrefs

Sequence in context: A181208 A175209 A141840 * A255576 A065404 A327496

Adjacent sequences: A203278 A203279 A203280 * A203282 A203283 A203284

Keyword

nonn

Author

R. H. Hardin Dec 31 2011

Status

approved