87827

Appears in sequences

• Number of triangles that can be built from rods with lengths 1,2,...,n by using and concatenating not necessarily all rods.at n=18A160456
• 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 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).at n=21A192707