Numbers of edges of regular polygons constructible with ruler (or, more precisely, an unmarked straightedge) and compass.

A003401

Numbers of edges of regular polygons constructible with ruler (or, more precisely, an unmarked straightedge) and compass.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =8a(7) =10a(8) =12a(9) =15a(10) =16a(11) =17a(12) =20a(13) =24a(14) =30a(15) =32a(16) =34a(17) =40a(18) =48a(19) =51a(20) =60a(21) =64a(22) =68a(23) =80a(24) =85a(25) =96a(26) =102a(27) =120a(28) =128a(29) =136

External references