A209840 Number of (n+1)X(n+1) 0..3 arrays with every 2X2 subblock having one or two distinct values, and new values 0..3 introduced in row major order

8, 451, 115435, 128454587, 595515461627, 11360964645748987, 886072158946966616059, 282112635103346805387587595

Offset

1,1

Comments

Diagonal of A209848

Links

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

Example

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

Crossrefs

Sequence in context: A012740 A042525 A028449 * A187049 A367707 A221157

Adjacent sequences: A209837 A209838 A209839 * A209841 A209842 A209843

Keyword

nonn

Author

R. H. Hardin Mar 14 2012

Status

approved