A208291 Number of 7 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.

14, 196, 966, 6650, 40376, 256774, 1604862, 10095932, 63357434, 397965218, 2498872432, 15692738782, 98544531778, 618833962068, 3886089661790, 24403526661710, 153246991242128, 962346508543154, 6043255215031230

Offset

1,1

Comments

Row 7 of A208287.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) + 16*a(n-2) - 7*a(n-3) - 23*a(n-4) + 2*a(n-5) + 9*a(n-6) - a(n-8).

Empirical g.f.: 14*x*(1 + x)*(1 + 9*x - 12*x^2 - 6*x^3 + 7*x^4 + x^5 - x^6) / (1 - 4*x - 16*x^2 + 7*x^3 + 23*x^4 - 2*x^5 - 9*x^6 + x^8). - Colin Barker, Jun 30 2018

Example

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

Crossrefs

Cf. A208287.

Sequence in context: A207407 A207708 A207253 * A207439 A207445 A207429

Adjacent sequences: A208288 A208289 A208290 * A208292 A208293 A208294

Keyword

nonn

Author

R. H. Hardin, Feb 25 2012

Status

approved