A303794 Number of nX2 0..1 arrays with every element unequal to 0, 1, 2 or 4 king-move adjacent elements, with upper left element zero.

2, 4, 12, 24, 64, 184, 432, 1088, 2944, 7360, 18496, 48384, 123392, 312320, 804864, 2061824, 5248000, 13449216, 34455552, 87961600, 225038336, 576143360, 1472741376, 3766452224, 9638051840, 24648581120, 63037702144, 161266270208

Offset

1,1

Comments

Column 2 of A303800.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +8*a(n-3) -8*a(n-4) -8*a(n-5) for n>6

Example

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

Crossrefs

Cf. A303800.

Sequence in context: A036045 A331392 A100538 * A135139 A161894 A062177

Adjacent sequences: A303791 A303792 A303793 * A303795 A303796 A303797

Keyword

nonn

Author

R. H. Hardin, Apr 30 2018

Status

approved