G.f.: A(x) = 1 + x*(1 + x*(1 + x*(...(1 + x*(...)^(2n))...)^6)^4)^2.
A138212
G.f.: A(x) = 1 + x*(1 + x*(1 + x*(...(1 + x*(...)^(2n))...)^6)^4)^2.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =9a(4) =68a(5) =732a(6) =10250a(7) =176654a(8) =3613044a(9) =85476720a(10) =2295275372a(11) =68949496421
External references
- oeis: A138212