The sequence lambda(3,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly three starting and/or finishing points.
A058809
The sequence lambda(3,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly three starting and/or finishing points.
Terms
- a(0) =0a(1) =0a(2) =6a(3) =24a(4) =78a(5) =240a(6) =726a(7) =2184a(8) =6558a(9) =19680a(10) =59046a(11) =177144a(12) =531438a(13) =1594320a(14) =4782966a(15) =14348904a(16) =43046718a(17) =129140160a(18) =387420486a(19) =1162261464a(20) =3486784398a(21) =10460353200a(22) =31381059606a(23) =94143178824a(24) =282429536478a(25) =847288609440
External references
- oeis: A058809