A210835 Number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having three or four distinct values, and new values 0..3 introduced in lower triangle row major order

1, 20, 1112, 177896, 81799424, 108046477848, 410104032824992, 4472498652789147680, 140150219505059739808160, 12618876507902932236881155440, 3264615282814988284277931558564176

Offset

1,2

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Sequence in context: A224125 A324416 A177596 * A002305 A091535 A265654

Adjacent sequences: A210832 A210833 A210834 * A210836 A210837 A210838

Keyword

nonn

Author

R. H. Hardin Mar 27 2012

Status

approved