a(n) = (-1)^(n+1)*n!* [x^n](log(x + 1)/2 + log(3*x + 1)/6).
A321398
a(n) = (-1)^(n+1)*n!* [x^n](log(x + 1)/2 + log(3*x + 1)/6).
Terms
- a(0) =0a(1) =1a(2) =2a(3) =10a(4) =84a(5) =984a(6) =14640a(7) =262800a(8) =5513760a(9) =132289920a(10) =3571464960a(11) =107140320000
External references
- oeis: A321398