Number of ordered set partitions of {1,2,...,n} such that no part has the same size as any of its two immediate predecessors.
A261961
Number of ordered set partitions of {1,2,...,n} such that no part has the same size as any of its two immediate predecessors.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =7a(4) =9a(5) =31a(6) =403a(7) =1597a(8) =7913a(9) =68551a(10) =539691a(11) =4359037a(12) =48419715a(13) =560648557a(14) =4985097601a(15) =59798395027a(16) =869794249513
External references
- oeis: A261961