Q(1,n), where Q(m,k) is defined in A127080 and A127137.

Terms

a(0) =1a(1) =1a(2) =-1a(3) =-4a(4) =3a(5) =28a(6) =-15a(7) =-288a(8) =105a(9) =3984a(10) =-945a(11) =-70080a(12) =10395a(13) =1506240a(14) =-135135a(15) =-38384640a(16) =2027025a(17) =1133072640a(18) =-34459425a(19) =-38038533120a(20) =654729075a(22) =-13749310575a(24) =316234143225