G.f.: A(x) = 1+x*(1+2x*(1+3x*(...(1+n*x*(...)^2)^2...)^2)^2)^2.
A128318
G.f.: A(x) = 1+x*(1+2x*(1+3x*(...(1+n*x*(...)^2)^2...)^2)^2)^2.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =28a(4) =276a(5) =3480a(6) =53232a(7) =955524a(8) =19672320a(9) =456803328a(10) =11810032896a(11) =336463895808
External references
- oeis: A128318