A192698 Number of 2X3 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 2 zero-sum 3-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)

2, 8, 20, 54, 104, 190, 323, 529, 795, 1181, 1653, 2297, 3088, 4119, 5307, 6804, 8518, 10618, 13029, 15955, 19160, 22996, 27203, 32102, 37584, 43811, 50621, 58445, 66858, 76327, 86710, 98294, 110610, 124474, 139222, 155502, 173011, 192273, 212726

Offset

1,1

Comments

Column (2,3,n) of A192710

Links

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

Example

Some solutions for 2X3 <= 2*4^2
.-3..0..3...-1..0..1...-2.-1..3...-2.-1..3...-2.-2..4...-1.-1..2...-1.-1..2
.-3..1..2....0..0..0...-2..1..1...-2.-1..3...-1.-1..2....0..0..0...-1.-1..2

Crossrefs

Sequence in context: A133326 A285185 A302323 * A305050 A279898 A221066

Adjacent sequences: A192695 A192696 A192697 * A192699 A192700 A192701

Keyword

nonn

Author

R. H. Hardin Jul 07 2011

Status

approved