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

Terms

a(0) =4a(1) =8a(2) =60a(3) =60a(4) =188a(5) =152a(6) =380a(7) =356a(8) =644a(9) =600a(10) =980a(11) =868a(12) =1388a(13) =1304a(14) =1868a(15) =1780a(16) =2412a(17) =2296a(18) =3012a(19) =2924a(20) =3700a(21) =3592a(22) =4460a(23) =4276a(24) =5292a(25) =5136a(26) =6196a(27) =6020a(28) =7156a(29) =6960