Alternating factorials: n! - (n-1)! + (n-2)! - ... 1!.

A005165

Alternating factorials: n! - (n-1)! + (n-2)! - ... 1!.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =5a(4) =19a(5) =101a(6) =619a(7) =4421a(8) =35899a(9) =326981a(10) =3301819a(11) =36614981a(12) =442386619a(13) =5784634181a(14) =81393657019

External references