Coefficients of ménage hit polynomials.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =8a(5) =35a(6) =211a(7) =1459a(8) =11584a(9) =103605a(10) =1030805a(11) =11291237a(12) =135015896a(13) =1749915271a(14) =24435107047a(15) =365696282855