G.f. A(x) satisfies: A(x) = 1 + x*A(x)*(1 + 2*x*A(x))/(1 - x*A(x) - x^2*A(x)^2).
A307411
G.f. A(x) satisfies: A(x) = 1 + x*A(x)*(1 + 2*x*A(x))/(1 - x*A(x) - x^2*A(x)^2).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =14a(4) =60a(5) =267a(6) =1254a(7) =6071a(8) =30156a(9) =152714a(10) =785682a(11) =4094752a(12) =21573258a(13) =114709363a(14) =614777462a(15) =3317589966a(16) =18011350796a(17) =98307220409a(18) =539121535194
External references
- oeis: A307411