-1962domain: ZAppears in sequencesExpansion of -(1+x^2)/((x^2+4*x+1)*(x^2-2*x-1)).at n=5A111644G.f.: Im((2*i; x)_oo), where (a; q)_oo is the q-Pochhammer symbol, i = sqrt(-1).at n=30A292140