A210819 Number of (n+1) X (n+1) 0..3 symmetric matrices containing all values 0..3 with every 2 X 2 subblock having one, two or three distinct values, and new values 0..3 introduced in lower triangle row major order.

0, 49, 23161, 22911278, 69542484194, 729154389280269, 27471650645869518237, 3762964490348482852461426, 1879310211105558770807436764190, 3424003001550934968214802269585406825

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n = 1..11

Example

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

Crossrefs

Sequence in context: A013741 A178190 A319941 * A173171 A100418 A369698

Adjacent sequences: A210816 A210817 A210818 * A210820 A210821 A210822

Keyword

nonn

Author

R. H. Hardin, Mar 27 2012

Status

approved