A192694 Number of 1X7 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 1 zero-sum 7-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)

2, 9, 36, 110, 277, 634, 1304, 2492, 4430, 7559, 12260, 19272, 29251, 43339, 62515, 88501, 122666, 167322, 224735, 297919, 389439, 504010, 644682, 817003, 1025762, 1278054, 1578938, 1938210, 2360862, 2859571, 3441853, 4122058, 4907573, 5817118

Offset

1,1

Comments

Column (1,7,n) of A192710

Links

R. H. Hardin, Table of n, a(n) for n = 1..141

Example

Some solutions for 1X7 <= 2*4^2
.-2.-2.-2..0..1..1..4...-2.-2.-1..0..1..2..2...-2.-2..0..1..1..1..1

Crossrefs

Sequence in context: A175261 A086556 A319012 * A192702 A073989 A288834

Adjacent sequences: A192691 A192692 A192693 * A192695 A192696 A192697

Keyword

nonn

Author

R. H. Hardin Jul 07 2011

Status

approved