A318077 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

3, 4, 5, 11, 18, 32, 54, 98, 173, 315, 559, 1008, 1813, 3290, 5928, 10716, 19352, 35036, 63355, 114651, 207352, 375184, 678789, 1228507, 2222990, 4022469, 7278193, 13171060, 23835243, 43132890, 78050078, 141238045, 255588327, 462524188

Offset

1,1

Comments

Column 3 of A318082.

Links

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

Formula

Empirical: a(n) = a(n-1) +8*a(n-4) -2*a(n-5) -24*a(n-8) -3*a(n-9) +34*a(n-12) +4*a(n-13) -24*a(n-16) -a(n-17) +8*a(n-20) -a(n-24)

Example

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

Crossrefs

Cf. A318082.

Sequence in context: A280255 A361517 A276542 * A074221 A341785 A052276

Adjacent sequences: A318074 A318075 A318076 * A318078 A318079 A318080

Keyword

nonn

Author

R. H. Hardin, Aug 15 2018

Status

approved