Class numbers associated with terms of A001990.

Terms

a(0) =2a(1) =2a(2) =2a(3) =2a(4) =2a(5) =2a(6) =2a(7) =2a(8) =46a(9) =46a(10) =46a(11) =46a(12) =46a(13) =46a(14) =406a(15) =718a(16) =950a(17) =950a(18) =950a(19) =1698a(20) =1698a(21) =1698a(22) =1698a(23) =1698a(24) =3990a(25) =3990a(26) =3990a(27) =53510a(28) =77970a(29) =89478