A210831 Number of (n+1) X (n+1) 0..3 symmetric matrices with every 2 X 2 subblock having two or three distinct values, and new values 0..3 introduced in lower triangle row major order.

4, 141, 25169, 16941289, 40820607681, 350983455561087, 10767951776455515799, 1178739099906082214413048, 460405515303453536692441783335, 641654973151502496777935760164666385

Offset

1,1

Links

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

Example

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

Crossrefs

Sequence in context: A262653 A299061 A299722 * A247483 A293752 A299833

Adjacent sequences: A210828 A210829 A210830 * A210832 A210833 A210834

Keyword

nonn

Author

R. H. Hardin, Mar 27 2012

Status

approved