Number of inequivalent height 1 degree n polynomials with nonzero constant term.

Terms

a(0) =1a(1) =4a(2) =6a(3) =21a(4) =45a(5) =144a(6) =378a(7) =1161a(8) =3321a(9) =10044a(10) =29646a(11) =89181a(12) =266085a(13) =798984a(14) =2392578a(15) =7179921a(16) =21526641a(17) =64586484a(18) =193720086a(19) =581179941a(20) =1743421725a(21) =5230324224a(22) =15690618378a(23) =47072032281a(24) =141215033961a(25) =423645633324