141430680

Appears in sequences

• Number of unrooted triangulations with reflection symmetry of a disk with 2 internal nodes and n+3 nodes on the boundary.at n=28A005509
• Expansion of 1/(1-4*x)^(19/2).at n=7A020930
• Number of nonnegative integer 4 X 4 matrices with sum of elements equal to n, up to rotational symmetry.at n=17A054773
• G.f. satisfies: A(x) = 1 + 2*x*sqrt(A(x)/A(-x)).at n=35A198786