A207089 Number of 3 X n 0..1 arrays avoiding 0 0 0 horizontally and 0 0 1 vertically.

7, 49, 241, 1393, 7915, 44065, 248525, 1398065, 7855615, 44186849, 248469913, 1397116033, 7856468163, 44178243889, 248421665301, 1396925252001, 7855169243255, 44171085215953, 248382373987585, 1396700728871121

Offset

1,1

Comments

Row 3 of A207088.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 11*a(n-2) + 48*a(n-3) + 29*a(n-4) + 6*a(n-5) - 111*a(n-6) - 8*a(n-7) - 32*a(n-8) + 64*a(n-9).

Empirical g.f.: x*(7 + 35*x + 66*x^2 + 36*x^3 - 77*x^4 - 119*x^5 - 40*x^6 + 32*x^7 + 64*x^8) / (1 - 2*x - 11*x^2 - 48*x^3 - 29*x^4 - 6*x^5 + 111*x^6 + 8*x^7 + 32*x^8 - 64*x^9). - Colin Barker, Mar 04 2018

Example

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

Crossrefs

Cf. A207088.

Sequence in context: A223947 A207083 A207177 * A375610 A362392 A224150

Adjacent sequences: A207086 A207087 A207088 * A207090 A207091 A207092

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved