G.f. satisfies: A(x) = (1 - x*A(x))^2 * (2*A(x) - 1).
A231556
G.f. satisfies: A(x) = (1 - x*A(x))^2 * (2*A(x) - 1).
Terms
- a(0) =1a(1) =2a(2) =11a(3) =74a(4) =556a(5) =4472a(6) =37667a(7) =328010a(8) =2929230a(9) =26679916a(10) =246889782a(11) =2314629836a(12) =21937826010a(13) =209856958820
External references
- oeis: A231556