A318011 Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

4, 28, 118, 508, 2130, 8971, 37700, 158613, 667178, 2806643, 11806334, 49664719, 208919728, 878843413, 3696948061, 15551606501, 65419489183, 275194053961, 1157633112776, 4869707055676, 20484941672721, 86172090154282

Offset

1,1

Comments

Column 3 of A318016.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +5*a(n-2) +3*a(n-4) -4*a(n-5) -11*a(n-6) -6*a(n-7) -a(n-8) -4*a(n-9) -4*a(n-10) -a(n-11) for n>14

Example

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

Crossrefs

Cf. A318016.

Sequence in context: A183469 A058227 A296392 * A328685 A212900 A196514

Adjacent sequences: A318008 A318009 A318010 * A318012 A318013 A318014

Keyword

nonn

Author

R. H. Hardin, Aug 12 2018

Status

approved