Number of set partitions of [n] such that for each pair of blocks (b,c) with b<c at least one pair of consecutive numbers (i,i+1) exists with i member of b and i+1 member of c or i member of c and i+1 member of b.
A272301
Number of set partitions of [n] such that for each pair of blocks (b,c) with b<c at least one pair of consecutive numbers (i,i+1) exists with i member of b and i+1 member of c or i member of c and i+1 member of b.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =23a(6) =66a(7) =204a(8) =664a(9) =2273a(10) =8283a(11) =32463a(12) =136434a(13) =605848
External references
- oeis: A272301