A213957 Number of n X n 0..3 matrices with row and column i=1..n having sum <= i*3

4, 120, 32060, 74323976, 1494988224948, 261421322089741976, 398278555474658144086480, 5298226825488439815883527067288

Offset

1,1

Comments

Column 3 of A213962

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for n=4
..0..0..1..2....1..0..0..0....3..0..0..0....3..0..0..0....3..0..0..0
..0..3..3..0....0..3..1..2....0..1..1..1....0..3..3..0....0..2..2..0
..1..0..1..2....1..0..1..3....0..1..2..3....0..1..3..3....0..3..1..3
..1..1..0..0....1..3..3..1....0..1..2..0....0..1..1..1....0..0..3..3

Crossrefs

Sequence in context: A307935 A001332 A071304 * A006607 A286757 A239187

Adjacent sequences: A213954 A213955 A213956 * A213958 A213959 A213960

Keyword

nonn

Author

R. H. Hardin Jun 28 2012

Status

approved