A211108 1/4 the number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having one, three or four distinct values

7, 145, 8869, 1551481, 784712137, 1145192936557, 4823916698572867, 58647466694975620939, 2057932010076596938468321, 208422415794469123178956493563

Offset

1,1

Links

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

Example

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

Crossrefs

Sequence in context: A102059 A064624 A342113 * A251668 A048935 A291677

Adjacent sequences: A211105 A211106 A211107 * A211109 A211110 A211111

Keyword

nonn

Author

R. H. Hardin Mar 31 2012

Status

approved