859295

Appears in sequences

• Number of permutations of length n which avoid the patterns 1423, 3421.at n=11A116710
• Number of 3X3 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 3 zero-sum 3-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).at n=21A192702