A204859 Number of (n+2)X(n+2) 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly two different ways, and new values 0..1 introduced in row major order

102, 1648, 36865, 1193734, 59491439, 4356486501, 463699765823, 75133672706401

Offset

1,1

Comments

Diagonal of A204867

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A206171 A199830 A200452 * A205425 A206651 A163435

Adjacent sequences: A204856 A204857 A204858 * A204860 A204861 A204862

Keyword

nonn

Author

R. H. Hardin Jan 20 2012

Status

approved