A210821 Number of (n+1)X(n+1) 0..3 symmetric matrices containing all values 0..3 with every 2X2 subblock having one, two or four distinct values, and new values 0..3 introduced in lower triangle row major order

0, 5, 536, 69967, 14851443, 5745072271, 4267026118300, 6252252369058803, 18347836198388369328, 108778622095860972769932

Offset

1,2

Links

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

Example

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

Crossrefs

Sequence in context: A067446 A249895 A241325 * A302222 A302668 A302470

Adjacent sequences: A210818 A210819 A210820 * A210822 A210823 A210824

Keyword

nonn

Author

R. H. Hardin Mar 27 2012

Status

approved