A192765 Number of n X n symmetric 0..2 arrays with each element equal to at least one horizontal or vertical neighbor, containing at least one 2 and with new values 0..2 introduced in lower triangular row major order.

0, 0, 0, 73, 6486, 1127280, 455878230, 457521123971, 1154811828698984, 7352963503841306070, 118143132683839293396707, 4790379790527104234486857472, 490170667488489136298923882507851

Offset

1,4

Links

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

Example

Some solutions for 4X4
..0..0..1..1....0..0..2..2....0..0..0..1....0..0..1..2....0..0..0..2
..0..0..2..1....0..1..1..2....0..0..1..1....0..0..1..2....0..0..1..2
..1..2..2..1....2..1..2..2....0..1..1..2....1..1..1..1....0..1..1..0
..1..1..1..1....2..2..2..2....1..1..2..2....2..2..1..1....2..2..0..0

Crossrefs

Sequence in context: A015260 A089788 A292013 * A177094 A116241 A105322

Adjacent sequences: A192762 A192763 A192764 * A192766 A192767 A192768

Keyword

nonn

Author

R. H. Hardin, Jul 09 2011

Status

approved