A192705 Number of 5X2 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 5 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)

2, 6, 14, 29, 56, 101, 166, 267, 407, 604, 865, 1211, 1659, 2236, 2956, 3861, 4949, 6299, 7906, 9849, 12120, 14817, 17958, 21641, 25859, 30753, 36318, 42732, 49917, 58116, 67296, 77693, 89219, 102175, 116527, 132515, 150117, 169602, 191013, 214662

Offset

1,1

Comments

Column (5,2,n) of A192710

Links

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

Example

Some solutions for 5X2 <= 2*4^2
.-3..3...-2..2...-2..2...-1..1...-1..1...-2..2...-3..3...-3..3...-3..3...-2..2
.-1..1...-1..1...-2..2...-1..1...-1..1...-2..2...-1..1....0..0...-1..1...-2..2
.-1..1...-1..1...-1..1....0..0...-1..1...-2..2...-1..1....0..0....0..0...-2..2
.-1..1....0..0...-1..1....0..0....0..0...-2..2...-1..1....0..0....0..0....0..0
.-1..1....0..0...-1..1....0..0....0..0....0..0....0..0....0..0....0..0....0..0

Crossrefs

Sequence in context: A321027 A214907 A169948 * A123991 A112511 A143702

Adjacent sequences: A192702 A192703 A192704 * A192706 A192707 A192708

Keyword

nonn

Author

R. H. Hardin Jul 07 2011

Status

approved