A297459 Number of 3 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0 or 2 neighboring 1s.

8, 19, 92, 285, 1143, 3933, 14817, 52868, 194822, 704284, 2575201, 9352440, 34103042, 124055943, 451921339, 1644897204, 5990104595, 21807171062, 79403933671, 289093577711, 1052597637063, 3832392357045, 13953632474038

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 4*a(n-2) - 7*a(n-3) + 8*a(n-4) - 19*a(n-5) + 8*a(n-6) + 2*a(n-8).

Empirical g.f.: x*(8 - 5*x + 3*x^2 - 11*x^3 - 11*x^4 + 8*x^5 + 2*x^6 + 2*x^7) / (1 - 3*x - 4*x^2 + 7*x^3 - 8*x^4 + 19*x^5 - 8*x^6 - 2*x^8). - Colin Barker, Feb 28 2019

Example

Some solutions for n=7:
..0..0..1..0..1..1..1. .0..0..1..0..1..0..1. .0..0..0..0..0..0..0
..1..0..0..0..0..1..0. .1..0..0..0..1..0..1. .0..0..0..0..1..0..1
..1..0..1..0..0..1..0. .0..0..0..0..0..0..0. .1..0..1..0..0..0..1

Crossrefs

Row 3 of A297457.

Sequence in context: A057452 A091560 A061877 * A297696 A242188 A119284

Adjacent sequences: A297456 A297457 A297458 * A297460 A297461 A297462

Keyword

nonn

Author

R. H. Hardin, Dec 30 2017

Status

approved