a(n) = n!/A124901(n).

Terms

a(0) =2a(1) =12a(2) =30a(3) =240a(4) =720a(5) =60480a(6) =60480a(7) =7983360a(8) =1108800a(9) =518918400a(10) =21794572800a(11) =62270208000a(12) =87178291200a(14) =2