A269048 Number of n X 4 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two not more than once.

60, 360, 3078, 24192, 183072, 1350672, 9779808, 69793968, 492374976, 3441051984, 23861339424, 164375084016, 1125975740544, 7675458754704, 52099028628960, 352309891913520, 2374503933353280, 15956129491021776, 106934858162261664

Offset

1,1

Links

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

Formula

Empirical: a(n) = 14*a(n-1) - 57*a(n-2) + 56*a(n-3) - 16*a(n-4) for n>5.

Empirical g.f.: 6*x*(10 - 80*x + 243*x^2 - 290*x^3 + 105*x^4) / (1 - 7*x + 4*x^2)^2. - Colin Barker, Jan 18 2019

Example

Some solutions for n=4:
..0..1..2..0. .2..1..2..1. .1..2..1..2. .0..0..0..1. .2..1..1..2
..0..1..0..1. .2..1..0..1. .1..2..1..2. .0..0..0..0. .2..2..2..2
..0..0..0..0. .2..1..2..0. .2..2..2..2. .0..0..0..1. .2..2..2..1
..0..1..0..0. .2..1..0..1. .1..1..2..1. .1..0..0..0. .2..1..2..1

Crossrefs

Column 4 of A269052.

Sequence in context: A024184 A293615 A119631 * A056428 A056419 A060489

Adjacent sequences: A269045 A269046 A269047 * A269049 A269050 A269051

Keyword

nonn

Author

R. H. Hardin, Feb 18 2016

Status

approved