A211104 1/4 the number of (n+1)X(n+1) 0..3 symmetric matrices with every 2X2 subblock having two or three distinct values

15, 795, 150501, 101638401, 244923340737, 2105900715375957, 64607710656824916891, 7072434599436128908889787, 2762433091820721094887987355053, 3849929838909014980590084143791140141

Offset

1,1

Links

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

Example

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

Crossrefs

Sequence in context: A267754 A317798 A280310 * A279493 A183821 A301312

Adjacent sequences: A211101 A211102 A211103 * A211105 A211106 A211107

Keyword

nonn

Author

R. H. Hardin Mar 31 2012

Status

approved