A304215 Number of n X n 0..1 arrays with every element unequal to 0, 1, 3 or 8 king-move adjacent elements, with upper left element zero.

1, 5, 10, 32, 141, 740, 4263, 33924, 451917, 7831308, 167764973, 5472669192, 258530463654, 15734556958302, 1343566924722008, 166506641101860333, 27977584863900148454, 6451992368321000124567, 2112336251628682183231929

Offset

1,2

Comments

Diagonal of A304221.

Links

Table of n, a(n) for n=1..19.

Example

Some solutions for n=7
..0..1..1..1..1..1..1. .0..1..1..1..1..1..0. .0..0..0..0..0..0..1
..1..1..1..1..1..1..1. .1..1..1..1..1..1..1. .0..0..0..0..0..0..0
..1..1..1..1..1..1..1. .1..1..1..1..1..1..1. .0..0..1..0..0..0..0
..1..1..1..1..1..1..1. .1..1..1..1..1..1..1. .0..0..0..0..0..0..0
..1..1..1..1..1..1..1. .1..1..1..0..1..1..1. .0..0..0..0..0..0..0
..1..1..1..1..1..1..0. .1..1..1..1..1..1..1. .0..0..0..0..0..0..1
..1..1..1..1..1..0..0. .1..1..1..1..1..1..1. .0..0..0..0..0..1..1

Crossrefs

Cf. A304221.

Sequence in context: A094234 A052538 A240413 * A073705 A355900 A328130

Adjacent sequences: A304212 A304213 A304214 * A304216 A304217 A304218

Keyword

nonn

Author

R. H. Hardin, May 08 2018

Status

approved