Number of crossings in a regular drawing of the complete bipartite graph K(n,n).

Terms

a(0) =0a(1) =1a(2) =7a(3) =27a(4) =65a(5) =147a(6) =261a(7) =461a(8) =737a(9) =1143a(10) =1637a(11) =2349a(12) =3217a(13) =4401a(14) =5769a(15) =7457a(16) =9433a(17) =11945a(18) =14753a(19) =18235a(20) =22173a(21) =26771a(22) =31801a(23) =37813a(24) =44449a(25) =52161a(26) =60489a(27) =69955a(28) =80289a(29) =92203