a(n)=(n-1)-st elementary symmetric function of the first n terms of (2, -4, 6, -8, 10, ...).

A203238

a(n)=(n-1)-st elementary symmetric function of the first n terms of (2, -4, 6, -8, 10, ...).

Terms

    a(0) =1a(1) =-2a(2) =-20a(3) =112a(4) =1504a(5) =-14208a(6) =-244992a(7) =3274752a(8) =69267456a(9) =-1199554560a(10) =-30106091520a(11) =640796590080

External references