A283574 Number of 3Xn 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element.

0, 16, 169, 674, 4313, 21186, 104464, 513458, 2431143, 11478378, 53471911, 246887096, 1132514276, 5160569268, 23395062541, 105570183858, 474452680669, 2124725208078, 9484785230640, 42219767106150, 187451695326747

Offset

1,2

Comments

Row 3 of A283572.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +10*a(n-2) -6*a(n-3) -105*a(n-4) -108*a(n-5) -85*a(n-6) -14*a(n-7) -250*a(n-8) +176*a(n-9) -145*a(n-10) +44*a(n-11) -4*a(n-12)

Example

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

Crossrefs

Cf. A283572.

Sequence in context: A205247 A067713 A017210 * A067711 A068175 A238976

Adjacent sequences: A283571 A283572 A283573 * A283575 A283576 A283577

Keyword

nonn

Author

R. H. Hardin, Mar 11 2017

Status

approved