A210809 Number of (n+1)X(n+1) 0..2 symmetric matrices containing all values 0..2 with every 2X2 subblock having three distinct values, and new values 0..2 introduced in lower triangle row major order

1, 4, 25, 249, 4003, 103776, 4345693, 293974075, 32139729821, 5678473177751, 1621605531925261, 748478713754793757, 558410639828147749314

Offset

1,2

Links

Table of n, a(n) for n=1..13.

Example

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

Crossrefs

Sequence in context: A345105 A220192 A220356 * A071896 A065740 A308008

Adjacent sequences: A210806 A210807 A210808 * A210810 A210811 A210812

Keyword

nonn

Author

R. H. Hardin Mar 26 2012

Status

approved