A192711 Number of 10 X 2 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 10 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).

2, 6, 19, 49, 118, 259, 534, 1042, 1941, 3465, 5996, 10040, 16364, 26012, 40522, 61835, 92657, 136556, 198316, 283977, 401349, 560438, 774140, 1058263, 1432174, 1920672, 2554179, 3369134, 4409927, 5730887, 7397192, 9486111, 12090252, 15318436

Offset

1,1

Comments

Column (10,2,n) of A192710.

Links

R. H. Hardin, Table of n, a(n) for n = 1..86

Example

Some solutions for 10 X 2 <= 2*4^2
.-2..2...-3..3...-2..2...-1..1....0..0...-2..2...-3..3...-1..1...-3..3...-2..2
.-1..1...-2..2...-2..2...-1..1....0..0...-2..2...-2..2....0..0...-1..1...-1..1
.-1..1...-1..1...-2..2...-1..1....0..0...-2..2...-1..1....0..0....0..0...-1..1
.-1..1...-1..1...-1..1....0..0....0..0...-1..1....0..0....0..0....0..0...-1..1
..0..0...-1..1....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....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0

Crossrefs

Cf. A192710.

Sequence in context: A058081 A192709 A034533 * A192712 A214948 A192713

Adjacent sequences: A192708 A192709 A192710 * A192712 A192713 A192714

Keyword

nonn

Author

R. H. Hardin, Jul 07 2011

Status

approved