A211106 1/4 the number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having two or four distinct values

9, 147, 4275, 226299, 21796677, 3826732161, 1225785261321, 717092242514919, 766646778031785891, 1498740416067587909439

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Example

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

Crossrefs

Sequence in context: A299319 A241797 A222439 * A006691 A304312 A361066

Adjacent sequences: A211103 A211104 A211105 * A211107 A211108 A211109

Keyword

nonn

Author

R. H. Hardin Mar 31 2012

Status

approved