A207850 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 0 and 1 1 1 vertically

42, 1764, 6216, 35952, 185136, 1006572, 5346600, 28935984, 154692048, 835671396, 4480109592, 24171724080, 129787001904, 699638944620, 3760020085080, 20257347370848, 108927000309120, 586630343266884, 3155460147857976

Offset

1,1

Comments

Row 7 of A207845

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +40*a(n-2) -50*a(n-3) -511*a(n-4) +376*a(n-5) +2736*a(n-6) -1247*a(n-7) -7118*a(n-8) +2183*a(n-9) +9712*a(n-10) -2183*a(n-11) -7118*a(n-12) +1247*a(n-13) +2736*a(n-14) -376*a(n-15) -511*a(n-16) +50*a(n-17) +40*a(n-18) -2*a(n-19) -a(n-20) for n>21

Example

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

Crossrefs

Sequence in context: A208378 A208068 A207933 * A208839 A208687 A207351

Adjacent sequences: A207847 A207848 A207849 * A207851 A207852 A207853

Keyword

nonn

Author

R. H. Hardin Feb 21 2012

Status

approved