Numerator of Sum_{k=0..n} (-1)^k/k!.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =3a(5) =11a(6) =53a(7) =103a(8) =2119a(9) =16687a(10) =16481a(11) =1468457a(12) =16019531a(13) =63633137a(14) =2467007773a(15) =34361893981a(16) =15549624751