3441853

Appears in sequences

• Number of polyominoes with n cells that tile the plane by translation but not by 180-degree rotation (Conway criterion).at n=23A075199
• 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).at n=30A192694