Coefficients of ménage hit polynomials.

Terms

a(0) =2a(1) =0a(2) =0a(3) =8a(4) =30a(5) =192a(6) =1344a(7) =10800a(8) =97434a(9) =976000a(10) =10749024a(11) =129103992a(12) =1679495350a(13) =23525384064a(14) =353028802560