A207951 Number of 5Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically

16, 256, 1232, 5929, 18172, 55696, 133812, 321489, 662256, 1364224, 2526384, 4678569, 8011752, 13719616, 22123992, 35676729, 54856032, 84345856, 124764640, 184552225, 264364100, 378691600, 527969260, 736091161, 1002761760, 1366041600

Offset

1,1

Comments

Row 5 of A207949

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)

Example

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

Crossrefs

Sequence in context: A207920 A208700 A207256 * A207860 A207810 A208284

Adjacent sequences: A207948 A207949 A207950 * A207952 A207953 A207954

Keyword

nonn

Author

R. H. Hardin Feb 21 2012

Status

approved