A208382 Number of 6 X n 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

12, 144, 180, 900, 3200, 10660, 40740, 148240, 526900, 1931300, 7015680, 25336420, 92086020, 334206800, 1211147700, 4394975940, 15944933760, 57827661860, 209781161700, 761003136400, 2760390765620, 10013327220580, 36323344673280

Offset

1,1

Comments

Row 6 of A208379.

Links

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

Formula

Empirical: a(n) = a(n-1) + 4*a(n-2) + 17*a(n-3) + 11*a(n-4) - 4*a(n-5) + 16*a(n-6) for n>8.

Empirical g.f.: 4*x*(3 + 33*x - 3*x^2 - 15*x^3 - 250*x^4 - 184*x^5 + 96*x^6 - 256*x^7) / (1 - x - 4*x^2 - 17*x^3 - 11*x^4 + 4*x^5 - 16*x^6). - Colin Barker, Jul 02 2018

Example

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

Crossrefs

Cf. A208379.

Sequence in context: A004191 A051051 A328468 * A208070 A207603 A207029

Adjacent sequences: A208379 A208380 A208381 * A208383 A208384 A208385

Keyword

nonn

Author

R. H. Hardin, Feb 25 2012

Status

approved