-5815domain: ZAppears in sequencesa(n) = a(n-1) - (n-1)(n-2)a(n-2).at n=9A002019Expansion of e.g.f. sin(arctanh(x)), odd powers only.at n=4A102058Expansion of Product_{k>=0} (1-x^(4*k+3))^(4*k+3).at n=37A285213