914922domain: NAppears in sequencesG.f. satisfies: -1 = Product_{n>=1} (1-x^n) * (1 - x^n/A(x)) * (1 - x^(n-1)*A(x)), where g.f. A(x) = Sum_{n>=0} a(n)*2*(x/4)^n.at n=5A268300