Coefficients of ménage hit polynomials.

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =6a(5) =38a(6) =213a(7) =1479a(8) =11692a(9) =104364a(10) =1036809a(11) =11344859a(12) =135548466a(13) =1755739218a(14) =24504637741a(15) =366596136399