A300533 Number of nX2 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

1, 3, 5, 16, 40, 113, 304, 833, 2270, 6194, 16900, 46103, 125787, 343166, 936250, 2554294, 6968726, 19012299, 51870004, 141513486, 386081850, 1053321508, 2873707154, 7840144587, 21389746215, 58356225385, 159209417569, 434360490031

Offset

1,2

Comments

Column 2 of A300539.

Links

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

Formula

Empirical: a(n) = a(n-1) +4*a(n-2) +2*a(n-3) -a(n-6)

Example

Some solutions for n=5
..0..0. .0..0. .0..1. .0..0. .0..0. .0..0. .0..1. .0..1. .0..0. .0..1
..0..0. .0..1. .1..1. .0..0. .0..1. .0..0. .1..1. .1..1. .0..0. .1..1
..0..0. .0..0. .0..1. .0..1. .1..1. .0..1. .0..1. .0..0. .1..0. .1..0
..0..0. .1..0. .1..1. .0..0. .0..1. .1..1. .1..1. .0..0. .0..0. .0..0
..0..1. .0..0. .1..1. .0..0. .1..1. .1..0. .1..0. .0..1. .0..1. .0..0

Crossrefs

Cf. A300539.

Sequence in context: A123785 A121646 A226205 * A221783 A368409 A371868

Adjacent sequences: A300530 A300531 A300532 * A300534 A300535 A300536

Keyword

nonn

Author

R. H. Hardin, Mar 08 2018

Status

approved