Number of isomorphism classes of reduced Witt rings of fields with n orderings.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =3a(6) =3a(7) =6a(8) =6a(9) =9a(10) =9a(11) =16a(12) =16a(13) =24a(14) =24a(15) =42a(16) =42a(17) =64a(18) =64a(19) =105a(20) =105a(21) =159a(22) =159a(23) =258a(24) =258a(25) =390a(26) =390a(27) =614a(28) =614a(29) =925