%I
%S 2,6,17,39,85,167,309,546,919,1486,2338,3564,5300,7703,11016,15451,
%T 21303,28978,38908,51626,67686,87827,112967,144076,182028,228322,
%U 284414,351962,432504,528554,642212,776430,933563,1117263,1331217,1579771,1865945
%N Number of 7X2 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 7 zerosum 2vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations)
%C Column (7,2,n) of A192710
%H R. H. Hardin, <a href="/A192707/b192707.txt">Table of n, a(n) for n = 1..163</a>
%e Some solutions for 7X2 <= 2*4^2
%e .1..1...3..3...2..2...3..3...3..3...2..2...2..2...2..2...2..2...2..2
%e .1..1....0..0...1..1...1..1...1..1...1..1...1..1....0..0...2..2...2..2
%e .1..1....0..0...1..1....0..0...1..1...1..1....0..0....0..0...2..2....0..0
%e .1..1....0..0...1..1....0..0...1..1...1..1....0..0....0..0...1..1....0..0
%e .1..1....0..0....0..0....0..0...1..1...1..1....0..0....0..0...1..1....0..0
%e .1..1....0..0....0..0....0..0...1..1...1..1....0..0....0..0...1..1....0..0
%e ..0..0....0..0....0..0....0..0....0..0...1..1....0..0....0..0....0..0....0..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jul 07 2011
