A207952 Number of 6Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically

26, 676, 4238, 26569, 98126, 362404, 1007146, 2798929, 6501278, 15100996, 30983078, 63568729, 119052836, 222964624, 389322036, 679801329, 1122859818, 1854680356, 2928100406, 4622776081, 7029589490, 10689492100, 15748468190

Offset

1,1

Comments

Row 6 of A207949

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-2) -22*a(n-3) -44*a(n-4) +110*a(n-5) +110*a(n-6) -330*a(n-7) -165*a(n-8) +660*a(n-9) +132*a(n-10) -924*a(n-11) +924*a(n-13) -132*a(n-14) -660*a(n-15) +165*a(n-16) +330*a(n-17) -110*a(n-18) -110*a(n-19) +44*a(n-20) +22*a(n-21) -10*a(n-22) -2*a(n-23) +a(n-24)

Example

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

Crossrefs

Sequence in context: A207470 A207522 A207257 * A207861 A207811 A208285

Adjacent sequences: A207949 A207950 A207951 * A207953 A207954 A207955

Keyword

nonn

Author

R. H. Hardin Feb 21 2012

Status

approved