123088domain: NAppears in sequencesTheta series of E_8 lattice with respect to midpoint of edge.at n=19A045819Norm of coefficients in the series C(x) defined by C(x) = 1 + x*C(i*x)^2, where i^2 = -1.at n=10A193379Number of involutions of doubly alternating Baxter permutations of length n.at n=27A347546