Number of 8X2 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 8 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).

A192708

Number of 8X2 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 8 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).

Terms

    a(0) =2a(1) =6a(2) =18a(3) =43a(4) =97a(5) =199a(6) =385a(7) =707a(8) =1235a(9) =2072a(10) =3383a(11) =5336a(12) =8218a(13) =12341a(14) =18215a(15) =26362a(16) =37488a(17) =52464a(18) =72546a(19) =98944a(20) =133305a(21) =177633a(22) =234514a(23) =306557a(24) =397175a(25) =510188a(26) =650637a(27) =823774a(28) =1035586a(29) =1293255

External references