A274889 Number of n X n 0..2 arrays with no element equal to any value at offset (0,-1), (-1,-1) or (-2,0) and new values introduced in order 0..2.

1, 4, 16, 104, 913, 12217, 237807, 6843349, 292253909, 18485204565, 1735778832010, 242007116498916, 50034244634072936, 15365321608796091811

Offset

1,2

Comments

Diagonal of A274895.

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Cf. A274895.

Sequence in context: A203716 A330537 A136793 * A009630 A318695 A131043

Adjacent sequences: A274886 A274887 A274888 * A274890 A274891 A274892

Keyword

nonn

Author

R. H. Hardin, Jul 10 2016

Status

approved