130401

Appears in sequences

• Number of lower triangles of a 4 X 4 0..n array with no element differing from any of its horizontal or vertical neighbors by more than one.at n=19A194933
• Number of 6-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero.at n=7A208600
• G.f. B(x) satisfies: B(x) = x + 3*A(x)*C(x), where A(x) = x + 2*B(x)*C(x) and C(x) = x + 5*A(x)*B(x).at n=6A229809