Number of set partitions of [n] such that at least one pair of consecutive blocks (b,b+1) exists having no pair of consecutive numbers (i,i+1) with i member of b and i+1 member of b+1.
A271271
Number of set partitions of [n] such that at least one pair of consecutive blocks (b,b+1) exists having no pair of consecutive numbers (i,i+1) with i member of b and i+1 member of b+1.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =9a(6) =58a(7) =341a(8) =1983a(9) =11776a(10) =72345a(11) =462173a(12) =3075894a(13) =21330762a(14) =154050330a(15) =1157493707a(16) =9037925277a(17) =73244123107a(18) =615295131046
External references
- oeis: A271271