a(n) = 4*((n-1)! + 1) + n.

Terms

a(0) =9a(1) =10a(2) =15a(3) =32a(4) =105a(5) =490a(6) =2891a(7) =20172a(8) =161293a(9) =1451534a(10) =14515215a(11) =159667216a(12) =1916006417a(13) =24908083218a(14) =348713164819