155502

Appears in sequences

• Numbers d_n used in recurrence for series-parallel numbers.at n=21A036655
• Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 3,2 3,3 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155244
• Number of 2X3 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 3-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).at n=35A192698