a(n+2) = (2n+3)*a(n+1) + (n+1)^2*a(n), a(0) = 1, a(1) = 1.

A012244

a(n+2) = (2n+3)*a(n+1) + (n+1)^2*a(n), a(0) = 1, a(1) = 1.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =24a(4) =204a(5) =2220a(6) =29520a(7) =463680a(8) =8401680a(9) =172504080a(10) =3958113600a(11) =100370793600

External references