A208844 Number of 7 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 1 0 vertically.

35, 1225, 2485, 44275, 131355, 1644265, 6206445, 62470275, 277136755, 2417186345, 11980836805, 94860446835, 507738545195, 3762485058185, 21244807809085, 150403989092035, 881487114021955, 6046472018190345, 36369091148160085

Offset

1,1

Comments

Row 7 of A208840.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 33*a(n-2) - 32*a(n-3).

Empirical g.f.: 35*x*(1 + 33*x - 32*x^2) / (1 - 2*x - 33*x^2 + 32*x^3). - Colin Barker, Jul 07 2018

Example

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

Crossrefs

Cf. A208840.

Sequence in context: A207492 A207889 A208112 * A207665 A208006 A207568

Adjacent sequences: A208841 A208842 A208843 * A208845 A208846 A208847

Keyword

nonn

Author

R. H. Hardin, Mar 01 2012

Status

approved