A275221 Number of n X n 0..2 arrays with no element equal to any value at offset (-2,-1), (-2,1) or (-1,0) and new values introduced in order 0..2.

1, 6, 61, 1302, 64248, 6534900, 1368326231, 608741311725, 563051463762052

Offset

1,2

Comments

Diagonal of A275228.

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=4
..0..1..2..1. .0..0..1..2. .0..1..0..2. .0..1..0..2. .0..1..0..2
..1..0..1..2. .2..1..2..1. .1..0..1..1. .1..0..2..0. .1..2..1..0
..0..1..0..1. .1..2..1..0. .2..1..0..2. .0..2..0..1. .2..1..0..1
..1..0..1..2. .2..0..2..1. .1..2..2..0. .2..0..1..0. .1..0..1..0

Crossrefs

Cf. A275228.

Sequence in context: A127695 A144343 A022517 * A243455 A271965 A271683

Adjacent sequences: A275218 A275219 A275220 * A275222 A275223 A275224

Keyword

nonn

Author

R. H. Hardin, Jul 20 2016

Status

approved