a(n) = n! * C(n+2, 2) * 2^(n+1).

A014297

a(n) = n! * C(n+2, 2) * 2^(n+1).

Terms

    a(0) =2a(1) =12a(2) =96a(3) =960a(4) =11520a(5) =161280a(6) =2580480a(7) =46448640a(8) =928972800a(9) =20437401600a(10) =490497638400

External references