Hit polynomials.

Terms

a(0) =1a(1) =4a(2) =8a(3) =38a(4) =209a(5) =1400a(6) =10849a(7) =95516a(8) =938441a(9) =10179149a(10) =120748974a(11) =1554688240a(12) =21588485677a(13) =321561688748