a(n) is the number of regions formed by n-secting the angles of a nonagon (enneagon).

Terms

a(0) =1a(1) =18a(2) =127a(3) =162a(4) =388a(5) =468a(6) =154a(7) =846a(8) =1288a(9) =1422a(10) =1945a(11) =2106a(12) =2827a(13) =1260a(14) =3700a(15) =3870a(16) =4798a(17) =4950a(18) =5995a(19) =6318a(20) =4879a(21) =7524a(22) =8830a(23) =9108a(24) =10387a(25) =10764a(26) =12331a(27) =8730a(28) =13933a(29) =14454