Number of set partitions of [n] with maximal block length multiplicity equal to two.
A271731
Number of set partitions of [n] with maximal block length multiplicity equal to two.
Terms
- a(0) =1a(1) =0a(2) =9a(3) =25a(4) =70a(5) =406a(6) =2093a(7) =10935a(8) =41961a(9) =267751a(10) =1745040a(11) =9744384a(12) =60271016a(13) =369277000a(14) =2981920373a(15) =19297914599a(16) =136978951579
External references
- oeis: A271731