A210827 Number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having two distinct values, and new values 0..3 introduced in lower triangle row major order

3, 29, 548, 18908, 1182512, 131061397, 25883001692, 9078760225423, 5673881364653895, 6325974204854627570, 12606596349780734850457, 44979541448033730855929795

Offset

1,1

Links

Table of n, a(n) for n=1..12.

Example

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

Crossrefs

Sequence in context: A113871 A186451 A248828 * A092251 A304553 A326337

Adjacent sequences: A210824 A210825 A210826 * A210828 A210829 A210830

Keyword

nonn

Author

R. H. Hardin Mar 27 2012

Status

approved