a(n) = n!*Sum_{i=0..n-1} (n-i)*(-2)^i/(i+1)!.

Terms

a(0) =0a(1) =1a(2) =2a(3) =10a(4) =48a(5) =296a(6) =2080a(7) =16752a(8) =151424a(9) =1519744a(10) =16766208a(11) =201685760a(12) =2627316736a(13) =36847260672a(14) =553551644672