1683055

Appears in sequences

• Triangle read by rows: T(n,k) is the number of noncrossing connected graphs on n nodes on a circle, having exactly k four-sided faces, n>=2, 0<=k<=floor(n/2)-1.at n=21A094046
• Quartic product sequence: a(n) = Product_{k=1..(n-1)/2} (1 + m*cos(k*Pi/n)^2 + q*cos(k*Pi/n)^4), with m=12 and q = 3*4^3.at n=10A152096