A210818 Number of (n+1) X (n+1) 0..3 symmetric matrices containing all values 0..3 with every 2 X 2 subblock having two or three distinct values, and new values 0..3 introduced in lower triangle row major order.

0, 47, 18769, 15675953, 40094432569, 349773663772607, 10762101043733093559, 1178656962552052684421464, 460402167947340968868291699047, 641654577152679219502203022480885713

Offset

1,2

Links

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

Example

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

Crossrefs

Sequence in context: A267063 A287225 A033520 * A093940 A237512 A224468

Adjacent sequences: A210815 A210816 A210817 * A210819 A210820 A210821

Keyword

nonn

Author

R. H. Hardin, Mar 27 2012

Status

approved