A192701 Number of 3X2 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 3 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)

2, 5, 10, 16, 27, 42, 58, 80, 110, 143, 182, 226, 281, 343, 413, 489, 576, 676, 783, 901, 1035, 1172, 1328, 1493, 1674, 1872, 2086, 2308, 2544, 2805, 3069, 3364, 3679, 4000, 4348, 4709, 5096, 5493, 5926, 6366, 6832, 7330, 7841, 8380, 8950, 9528, 10134, 10766

Offset

1,1

Comments

Column (3,2,n) of A192710

Links

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

Example

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

Crossrefs

Sequence in context: A047992 A079984 A027613 * A258601 A264300 A326763

Adjacent sequences: A192698 A192699 A192700 * A192702 A192703 A192704

Keyword

nonn

Author

R. H. Hardin Jul 07 2011

Status

approved