1538560domain: NAppears in sequences1 + Sum_{n >= 1} Sum_{k = 0..n-1} (-1)^n*T(n,k)*y^(2*k)*x^(2*n)/(2*n)! = JacobiCN(x,y).at n=18A060627Number of independent vertex sets and vertex covers in the n-web graph.at n=9A287485