1872145027domain: NAppears in sequencesExpansion of g.f. A(x) satisfying 1 - 2*Sum_{n>=1} Product_{k=1..n} (x^(2*k-1) - 2*A(x)) = Product_{k>=1} (1 - x^(2*k)) * (1 + x^k - 2*A(x))^2 / (1 + x^(2*k) - 2*A(x))^2.at n=12A370345