A208504 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 0 and 1 1 1 vertically.

19, 361, 456, 1406, 4104, 12654, 37430, 114494, 341012, 1037552, 3103650, 9410776, 28227958, 85405038, 256622854, 775344932, 2332325696, 7040506202, 21193626760, 63940325966, 192562547974, 580744761326, 1749471290612, 5274981085968

Offset

1,1

Comments

Row 6 of A208501.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 7*a(n-2) - 11*a(n-3) - 4*a(n-4) + 4*a(n-5) for n>7.

Empirical g.f.: 19*x*(1 + 17*x - 21*x^2 - 96*x^3 + 113*x^4 + 52*x^5 - 40*x^6) / (1 - 2*x - 7*x^2 + 11*x^3 + 4*x^4 - 4*x^5). - Colin Barker, Jul 03 2018

Example

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

Crossrefs

Cf. A208501.

Sequence in context: A078368 A332798 A209227 * A207877 A207680 A223224

Adjacent sequences: A208501 A208502 A208503 * A208505 A208506 A208507

Keyword

nonn

Author

R. H. Hardin, Feb 27 2012

Status

approved