One-third of the even-indexed entries of A259056.

A259057

One-third of the even-indexed entries of A259056.

Terms

    a(0) =-1a(1) =20a(2) =-560a(3) =20160a(4) =-887040a(5) =46126080a(6) =-2767564800a(7) =188194406400

External references