A208024 Number of nX4 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 0 1 vertically

10, 100, 378, 1377, 4823, 17119, 61292, 218243, 776100, 2765576, 9852117, 35078967, 124935587, 444991022, 1584772385, 5644067960, 20101607046, 71591508557, 254970749655, 908076480129, 3234105068568, 11518206999371, 41021924800776

Offset

1,1

Comments

Column 4 of A208028

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +20*a(n-3) +27*a(n-4) +34*a(n-5) -21*a(n-6) -105*a(n-7) -149*a(n-8) +6*a(n-9) +254*a(n-10) +227*a(n-11) -101*a(n-12) -242*a(n-13) -93*a(n-14) +86*a(n-15) +77*a(n-16) +15*a(n-17) -34*a(n-18) -9*a(n-19) -5*a(n-20) +7*a(n-21) -2*a(n-22) -a(n-24) for n>25

Example

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

Crossrefs

Sequence in context: A207809 A208283 A208416 * A207804 A060522 A086115

Adjacent sequences: A208021 A208022 A208023 * A208025 A208026 A208027

Keyword

nonn

Author

R. H. Hardin Feb 22 2012

Status

approved