A203390 Number of n X n 0..3 arrays with every nonzero element less than or equal to some NW, E or S neighbor

1, 16, 7785, 18530502, 474618867194, 149902909246835321, 535800823449864962697227, 20614712434599379183066014500691, 8729478655533855038607697299128077953713

Offset

1,2

Comments

Diagonal of A203397

Links

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

Example

Some solutions for n=4
..2..3..1..3....1..0..0..0....2..1..1..0....0..2..3..3....1..3..1..3
..2..3..1..3....1..3..1..2....2..1..1..1....0..1..2..3....3..3..1..3
..3..3..3..3....1..3..2..2....2..2..2..1....2..3..1..1....1..3..3..3
..0..1..2..3....3..3..3..2....0..0..2..0....1..3..3..0....1..3..3..3

Crossrefs

Sequence in context: A097547 A088654 A079920 * A221085 A280845 A069986

Adjacent sequences: A203387 A203388 A203389 * A203391 A203392 A203393

Keyword

nonn

Author

R. H. Hardin Jan 01 2012

Status

approved