cp's OEIS Frontend

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).

%I A192700 #7 Jun 02 2025 04:12:49
%S A192700 2,13,75,361,1355,4257,11487,28113,62690,130088,253378,470284,832594,
%T A192700 1423302,2347627,3764623,5870541,8958955,13369172,19590712,28190894,
%U A192700 39941879,55749068,76863446,104549377,140705757,187241581,246861965
%N 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).
%C A192700 Column (2,5,n) of A192710
%H A192700 R. H. Hardin, <a href="/A192700/b192700.txt">Table of n, a(n) for n = 1..56</a>
%e A192700 Some solutions for 2X5 <= 2*4^2
%e A192700 .-3.-1..0..1..3...-2.-2..1..1..2...-2.-1.-1..2..2...-2.-1..1..1..1
%e A192700 .-2.-1..0..1..2...-2..0..0..0..2...-1.-1..0..1..1...-2..0..0..1..1
%K A192700 nonn
%O A192700 1,1
%A A192700 _R. H. Hardin_ Jul 07 2011