A214006 Number of n X n nonnegative integer matrices with row and column i=1..n having sum <= i*2

3, 54, 7722, 9318805, 98721672541, 9463992096711104, 8396505064286814402888

Offset

1,1

Comments

Column 2 of A214011

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for n=3
..0..2..0....0..0..0....2..0..0....2..0..0....0..0..0....0..0..0....0..0..1
..0..0..0....0..0..4....0..1..0....0..0..2....0..1..0....0..4..0....0..0..3
..0..0..5....0..1..0....0..0..0....0..1..2....0..2..0....1..0..1....0..3..0

Crossrefs

Sequence in context: A171739 A157568 A156911 * A154604 A188798 A334248

Adjacent sequences: A214003 A214004 A214005 * A214007 A214008 A214009

Keyword

nonn

Author

R. H. Hardin Jun 30 2012

Status

approved