A192706 Number of 6X2 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2*n^2 (number of collections of 6 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)

2, 6, 16, 34, 71, 135, 235, 396, 641, 993, 1496, 2193, 3136, 4398, 6065, 8214, 10949, 14438, 18760, 24151, 30736, 38755, 48448, 60129, 73970, 90426, 109793, 132568, 158991, 189853, 225331, 266394, 313294, 367015, 428094, 497667, 575969, 664608

Offset

1,1

Comments

Column (6,2,n) of A192710

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Example

Some solutions for 6X2 <= 2*4^2
.-2..2...-3..3...-1..1...-1..1...-2..2...-2..2...-3..3...-3..3...-1..1...-1..1
.-2..2...-2..2...-1..1...-1..1...-1..1...-2..2....0..0...-1..1...-1..1....0..0
.-1..1...-1..1....0..0...-1..1...-1..1...-1..1....0..0...-1..1...-1..1....0..0
..0..0....0..0....0..0....0..0...-1..1...-1..1....0..0....0..0...-1..1....0..0
..0..0....0..0....0..0....0..0...-1..1....0..0....0..0....0..0...-1..1....0..0
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0

Crossrefs

Sequence in context: A182994 A309691 A235792 * A248832 A280400 A199477

Adjacent sequences: A192703 A192704 A192705 * A192707 A192708 A192709

Keyword

nonn

Author

R. H. Hardin Jul 07 2011

Status

approved