a(n) = exp(-1/3) * Sum_{k>=0} (3*k - 1)^n / (3^k * k!).
A337039
a(n) = exp(-1/3) * Sum_{k>=0} (3*k - 1)^n / (3^k * k!).
Terms
- a(0) =1a(1) =0a(2) =3a(3) =9a(4) =54a(5) =351a(6) =2673a(7) =22842a(8) =216513a(9) =2248965a(10) =25351704a(11) =307699965a(12) =3995419365a(13) =55207193328a(14) =808078734999
External references
- oeis: A337039