Bi-diagonal inverse of [k<=n]*n!/(2k)!.

Terms

a(0) =1a(1) =-2a(2) =2a(3) =0a(4) =-24a(5) =12a(6) =0a(7) =0a(8) =-360a(9) =120a(10) =0a(11) =0a(12) =0a(13) =-6720a(14) =1680a(15) =0a(16) =0a(17) =0a(18) =0a(19) =-151200a(20) =30240a(21) =0a(22) =0a(23) =0a(24) =0a(25) =0a(26) =-3991680a(27) =665280a(28) =0a(29) =0