A203839 Number of n X n 0..3 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors

1, 4, 262, 84346, 215340781, 5191761888989, 962798716189325069

Offset

1,2

Comments

Diagonal of A203846

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A112982 A352332 A061788 * A052136 A089667 A119008

Adjacent sequences: A203836 A203837 A203838 * A203840 A203841 A203842

Keyword

nonn

Author

R. H. Hardin Jan 06 2012

Status

approved