a(n) = A029572(n) / 24.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =6a(7) =42a(8) =336a(9) =3024a(10) =27216a(11) =299376a(12) =3592512a(13) =46702656a(14) =653837184a(15) =9880206336a(16) =158083301376