A210822 Number of (n+1)X(n+1) 0..3 symmetric matrices containing all values 0..3 with every 2X2 subblock having three or four distinct values, and new values 0..3 introduced in lower triangle row major order.

0, 16, 1087, 177647, 81795421, 108046374072, 410104028479299, 4472498652495173605, 140150219505027600078339, 12618876507902926558407977689, 3264615282814988282656326026638915

Offset

1,2

Links

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

Example

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

Crossrefs

Sequence in context: A266066 A232571 A203096 * A265622 A144915 A209541

Adjacent sequences: A210819 A210820 A210821 * A210823 A210824 A210825

Keyword

nonn

Author

R. H. Hardin, Mar 27 2012

Status

approved