Number of regions in a regular 2n-gon when all vertices are connect by straight lines except for the n lines joining diametrically opposite vertices.

A368813

Number of regions in a regular 2n-gon when all vertices are connect by straight lines except for the n lines joining diametrically opposite vertices.

Terms

    a(0) =0a(1) =1a(2) =13a(3) =57a(4) =171a(5) =361a(6) =813a(7) =1489a(8) =2215a(9) =4081a(10) =6249a(11) =8329a(12) =13027a(13) =17977a(14) =20221a(15) =32033a(16) =41583a(17) =50545a(18) =66881a(19) =83161a(20) =93871a(21) =124521a(22) =150237a(23) =173233a(24) =213351a(25) =251473a(26) =285445a(27) =342889a(28) =397011a(29) =432121

External references