Number of interior points that are the intersections of exactly two chords in the configuration A006561(n).

A292104

Number of interior points that are the intersections of exactly two chords in the configuration A006561(n).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =5a(5) =12a(6) =35a(7) =40a(8) =126a(9) =140a(10) =330a(11) =228a(12) =715a(13) =644a(14) =1365a(15) =1168a(16) =2380a(17) =1512a(18) =3876a(19) =3360a(20) =5985a(21) =5280a(22) =8855a(23) =6144a(24) =12650a(25) =11284a(26) =17550a(27) =15680a(28) =23751a(29) =13800

External references