The sequence lambda(4,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly four starting and/or finishing points.
A059116
The sequence lambda(4,n), where lambda is defined in A055203. Number of ways of placing n identifiable positive intervals with a total of exactly four starting and/or finishing points.
Terms
- a(0) =0a(1) =0a(2) =6a(3) =114a(4) =978a(5) =6810a(6) =43746a(7) =271194a(8) =1653378a(9) =9998970a(10) =60229986a(11) =362088474a(12) =2174656578a(13) =13054316730a(14) =78345032226a(15) =470127588954
External references
- oeis: A059116