A213963 Number of 3X3 0..n matrices with row and column 1..3 having sum <= i*n.

138, 3186, 32060, 199735, 909900, 3323712, 10301232, 28115505, 69342790, 157454154, 333771516, 667605263, 1270560760, 2316187440, 4066346688, 6905893425, 11387501154, 18288711250, 28683554460, 44031375927, 66285794564

Offset: 1

Author

R. H. Hardin Jun 28 2012

Keywords

• nonn

Comments

Row 3 of A213962

Examples

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

Links

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

Formula

Empirical: a(n) = (n+3) *(n+2) *(449*n^5+3038*n^4+7759*n^3+9790*n^2+6264*n+1680) *(1+n)^2/10080.