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

Terms

a(0) =9a(1) =36a(2) =261a(3) =279a(4) =783a(5) =846a(6) =288a(7) =1557a(8) =2583a(9) =2664a(10) =3897a(11) =3996a(12) =5661a(13) =2214a(14) =7407a(15) =7425a(16) =9603a(17) =9549a(18) =11997a(19) =12231a(20) =9738a(21) =14607a(22) =17667a(23) =17730a(24) =20781a(25) =20997a(26) =24669a(27) =16515a(28) =27873a(29) =28278