a(n) = n*(a(n-1)-1) starting with a(0)=3.

Terms

a(0) =3a(1) =2a(2) =2a(3) =3a(4) =8a(5) =35a(6) =204a(7) =1421a(8) =11360a(9) =102231a(10) =1022300a(11) =11245289a(12) =134943456a(13) =1754264915a(14) =24559708796a(15) =368395631925