A214012 Number of 3X3 nonnegative integer matrices with row and column i=1..3 having sum <= i*n

271, 7722, 85639, 564041, 2663506, 9976732, 31499434, 87205393, 217519577, 498458246, 1064675833, 2143185161, 4101100212, 7511389208, 13241320196, 22569031649, 37334466803, 60131772546, 94551181659, 145479371081

Offset

1,1

Comments

Row 3 of A214011

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = (n+3) *(n+2) *(n+1) *(3493*n^6 +23853*n^5 +62185*n^4 +81783*n^3 +58531*n^2 +22470*n +3780)/22680;

Example

Some solutions for n=3
..0..0..1....0..0..2....3..0..0....0..0..3....0..0..3....0..0..0....2..0..0
..2..0..0....2..1..0....0..6..0....1..2..0....1..0..0....0..0..0....0..1..0
..0..6..0....0..0..5....0..0..9....2..1..0....0..3..4....0..4..0....1..2..0

Crossrefs

Sequence in context: A296038 A287232 A332978 * A303886 A305279 A005933

Adjacent sequences: A214009 A214010 A214011 * A214013 A214014 A214015

Keyword

nonn

Author

R. H. Hardin Jun 30 2012

Status

approved