E.g.f.: exp((3/2) * x * (2 + x)).

Terms

a(0) =1a(1) =3a(2) =12a(3) =54a(4) =270a(5) =1458a(6) =8424a(7) =51516a(8) =331452a(9) =2230740a(10) =15641424a(11) =113846472a(12) =857706408a(13) =6671592216a(14) =53465326560a(15) =440602852752