E.g.f. (1-2x)/(1-2x-x^2).

A052580

E.g.f. (1-2x)/(1-2x-x^2).

Terms

    a(0) =1a(1) =0a(2) =2a(3) =12a(4) =120a(5) =1440a(6) =20880a(7) =352800a(8) =6814080a(9) =148055040a(10) =3574368000a(11) =94922150400

External references