a(n) is the Severi degree for curves of degree n and cogenus 2.

Terms

a(0) =0a(1) =0a(2) =21a(3) =225a(4) =882a(5) =2370a(6) =5175a(7) =9891a(8) =17220a(9) =27972a(10) =43065a(11) =63525a(12) =90486a(13) =125190a(14) =168987a(15) =223335a(16) =289800a(17) =370056a(18) =465885a(19) =579177a(20) =711930a(21) =866250a(22) =1044351a(23) =1248555a(24) =1481292a(25) =1745100a(26) =2042625a(27) =2376621a(28) =2749950a(29) =3165582