1289624490

Appears in sequences

• a(n) = 3*(2*n)!/((n+2)!*(n-1)!).at n=18A000245
• a(n) = T(n, floor(n/2)), where T = Catalan triangle (A008315).at n=35A026008
• a(n) = 3*binomial(2n, n-1)/(n+2), n > 0, with a(0)=1.at n=18A071724
• Arises from enumeration of a certain class of partial zig-zag knight's paths on the square grid.at n=35A368379