a(n) is the Severi degree for curves of degree n and cogenus 4.

Terms

a(0) =0a(1) =0a(2) =0a(3) =666a(4) =36975a(5) =437517a(6) =2667375a(7) =11225145a(8) =37206936a(9) =104285790a(10) =257991042a(11) =579308220a(12) =1203756165a(13) =2347234131a(14) =4340067705a(15) =7670818467a(16) =13041558390a(17) =21436446060a(18) =34205577876a(19) =53166223470a(20) =80723690667a(21) =120014201385a(22) =175072295955a(23) =251025419421