A207406 Number of 6Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically

12, 144, 636, 2809, 8692, 26896, 68060, 172225, 380970, 842724, 1690038, 3389281, 6303584, 11723776, 20533728, 35964009, 59970000, 100000000, 160050000, 256160025, 395963700, 612067600, 918225100, 1377523225, 2013488750

Offset

1,1

Comments

Row 6 of A207403

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

Crossrefs

Sequence in context: A207946 A209653 A207073 * A207707 A207252 A208290

Adjacent sequences: A207403 A207404 A207405 * A207407 A207408 A207409

Keyword

nonn

Author

R. H. Hardin Feb 17 2012

Status

approved