A192700 Number of 2X5 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 5-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)

2, 13, 75, 361, 1355, 4257, 11487, 28113, 62690, 130088, 253378, 470284, 832594, 1423302, 2347627, 3764623, 5870541, 8958955, 13369172, 19590712, 28190894, 39941879, 55749068, 76863446, 104549377, 140705757, 187241581, 246861965

Offset

1,1

Comments

Column (2,5,n) of A192710

Links

R. H. Hardin, Table of n, a(n) for n = 1..56

Example

Some solutions for 2X5 <= 2*4^2
.-3.-1..0..1..3...-2.-2..1..1..2...-2.-1.-1..2..2...-2.-1..1..1..1
.-2.-1..0..1..2...-2..0..0..0..2...-1.-1..0..1..1...-2..0..0..1..1

Crossrefs

Sequence in context: A307288 A154357 A161130 * A007509 A077413 A024199

Adjacent sequences: A192697 A192698 A192699 * A192701 A192702 A192703

Keyword

nonn

Author

R. H. Hardin Jul 07 2011

Status

approved