Crossing number of the n-crown graph (conjectured).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =4a(5) =12a(6) =36a(7) =72a(8) =144a(9) =240a(10) =400a(11) =600a(12) =900a(13) =1260a(14) =1764a(15) =2352a(16) =3136a(17) =4032a(18) =5184a(19) =6480a(20) =8100a(21) =9900a(22) =12100a(23) =14520a(24) =17424a(25) =20592a(26) =24336a(27) =28392a(28) =33124a(29) =38220