Triangle read by rows: T(n,k) gives number of ways of arranging n chords on a circle with k simple intersections (i.e., no intersections with 3 or more chords) - positive values only.
A067311
Triangle read by rows: T(n,k) gives number of ways of arranging n chords on a circle with k simple intersections (i.e., no intersections with 3 or more chords) - positive values only.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =5a(5) =6a(6) =3a(7) =1a(8) =14a(9) =28a(10) =28a(11) =20a(12) =10a(13) =4a(14) =1a(15) =42a(16) =120a(17) =180a(18) =195a(19) =165a(20) =117a(21) =70a(22) =35a(23) =15a(24) =5a(25) =1a(26) =132a(27) =495a(28) =990a(29) =1430
External references
- oeis: A067311