Class numbers associated with terms of A001986.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =1a(9) =1a(10) =1a(11) =33a(12) =79a(13) =79a(14) =107a(15) =107a(16) =311a(17) =487a(18) =487a(19) =665a(20) =665a(21) =857a(22) =2293a(23) =3523a(24) =3523a(25) =3523a(26) =13909a(27) =13909a(28) =13909a(29) =26713