A303715 Number of nX4 0..1 arrays with every element unequal to 0, 1 or 5 king-move adjacent elements, with upper left element zero.

5, 5, 8, 17, 36, 76, 161, 349, 749, 1604, 3449, 7412, 15912, 34177, 73421, 157693, 338696, 727505, 1562612, 3356300, 7209009, 15484261, 33258581, 71436052, 153437513, 329568260, 707879240, 1520453249, 3265780149, 7014565813

Offset

1,1

Comments

Column 4 of A303719.

Links

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

Formula

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

Example

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

Crossrefs

Cf. A303719.

Sequence in context: A218333 A212533 A081287 * A204188 A347682 A334383

Adjacent sequences: A303712 A303713 A303714 * A303716 A303717 A303718

Keyword

nonn

Author

R. H. Hardin, Apr 29 2018

Status

approved